World 4 (Dr. Mario World)

World 4 is a haunted forest world in Dr. Mario World. It features a Ghost House on the world map. It is available since the initial version of this game.

When an area is cleared, Boos and Peepas appear. The viruses featured in the regular stages are red, green and light-blue.

Area 1

Image	Stage	Best Doctors	Overview
	Stage 121	Dr. Yoshi Dr. Toad	Starting with 21 capsules, the objective of this stage is to eliminate all viruses (21). This stage introduces dust viruses, which are viruses that are hidden in dust until a capsule lands next to it or an adjacent object is destroyed. If a valid match is made even though viruses in dust are not revealed, it will still be eliminated. This stage is shaped like a ghost, with exploders shaping its eyes. Some Brick Blocks are present in this stage. Surrounding the layout on the top and sides are Empty Blocks.
	Stage 122	Dr. Donkey Kong Dr. Luigi	Starting with 28 capsules, the objective of this stage is to eliminate all viruses (29). The only colors available in this stage are red and green. In this stage, there is a path of viruses interspersed with dust viruses. A red lock block is located between two Brick Blocks, which will unlock red cages containing viruses and a green lock block. The green cages contain viruses and Brick Blocks. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 34 to 28. The available colors are changed to red and green only. All Empty Blocks are replaced with Brick Blocks. The contents of two of the red cages in the top-right corner are changed from viruses to exploders. The contents of the dust cloud in row #3 is changed from a virus to a shell.
	Stage 123	Dr. Ludwig Dr. Waluigi	Starting with 30 capsules, the objective of this stage is to eliminate all viruses (33). In this stage, viruses are lined up along the sides, top and a row near the bottom, with most of them being half-frozen. In the middle, dust viruses are found above Brick Blocks. Two shells are located on the rightmost column. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 33 to 30. A shell is added in the rightmost of row #6. The rightmost half-frozen virus in row #4 is replaced with a shell.
	Stage 124	Dr. Fire Rosalina Dr. Toad	Starting with 36 capsules, the objective of this stage is to eliminate all viruses (51). In this stage, cages are lined up diagonally, one line containing viruses and another line containing floatie viruses. The corresponding lock blocks are found on the outside of the diagonal line with Brick Blocks.
	Stage 125	Dr. Boo Dr. Fire Mario	Starting with 37 capsules, the objective of this stage is to collect all virus coins (10). In this stage, there are two groups with two columns each has viruses each with four virus coins each, and in each group, the ones in the middle rows are half-frozen. In the middle column, there are fully-frozen viruses with exploders, and each virus cover a virus coin. Two columns with Brick Blocks and Empty Blocks are located between the middle column. The capsule amount is increased from 32 to 37 since version 1.3.5. Besides that, this stage is otherwise the same.
	Stage 126	Dr. Toadette Dr. Yoshi	Starting with 30 capsules, the objective of this stage is to eliminate all viruses (29). In this stage, a shell is in the middle of the stage where it is in the same row as two lock blocks and two floatie viruses. The cages form both a "v" and an upside-down "v". The Brick Blocks above and below the lock blocks contain hidden viruses. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 38 to 30. The virus in the middle of row #10 is replaced with a pop cannon. The Empty Blocks in row #6 are replaced with Brick Blocks. The caged viruses in the middle column are replaced with Brick Blocks.
	Stage 127	Dr. Waluigi Dr. Toad	Starting with 29 capsules, the objective of this stage is to eliminate all viruses (35). This stage is shaped like a spade that is mostly formed by dust viruses and a half-frozen lock block in the middle that corresponds to four caged viruses in the corners. Prior to March 18, 2021, the stage layout was different. The following changes were made: This stage is no longer labeled as "Hard". The middle dust virus in row #8 is changed to become a normal virus.
	Stage 128	Dr. Luma Dr. Fire Mario	Starting with 30 capsules, the objective of this stage is to eliminate all viruses (50). In this stage, there are two symmetrical groups of viruses that are in cages with the middle ones being free. There are viruses inside bubbles surrounded by Brick Blocks on the leftmost and rightmost columns, and a shell in the middle column in the top row. The Brick Blocks in the second and eighth columns contain lock blocks in the second row and hidden viruses in the other rows. The capsule amount is increased from 40 to 45 since version 1.3.5. Besides that, this stage is otherwise the same. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 45 to 30. The normal viruses in row #8 are replaced with exploders. The lock blocks are changed from being hidden in Brick Blocks to being inside bubbles. Viruses are added to the third and seventh spaces in both rows #3 and #4.
	Stage 129	Dr. Mario Dr. Waluigi	Starting with 39 capsules, the objective of this stage is to eliminate all viruses (39). In this stage, dust viruses are in the leftmost and rightmost columns, along with one in the middle column in the topmost row. Hidden viruses are found in the Brick Blocks in rows #3, #5 and #7, and some viruses are half-frozen and fully-frozen. Shells are hidden inside the middle Brick Blocks in rows #4 and #6. Prior to March 18, 2021, the stage layout was different. The following changes were made: All Empty Blocks are replaced with Brick Blocks. Of the new Brick Blocks, the middle ones in row #4 and #6 contain hidden shells.
	Stage 130	Dr. Yoshi Dr. Koopa Troopa	Starting with 28 capsules, the objective of this stage is to collect all coins from Coin Blocks (24). This stage is shaped like a flower. Viruses in cages are found next to Brick Blocks (all containing coins), with the corresponding lock block near the bottom row. An exploder is in the middle of the Brick Blocks. The capsule amount is increased from 25 to 28 since March 18, 2021. Besides that, this stage is otherwise the same.
	Stage 131	Dr. Fire Peach Dr. Piranha Plant	Starting with 33 capsules, the objective of this stage is to eliminate all viruses (34). This stage is shaped like a ghost flipped 90 degrees counter-clockwise. Five floatie viruses are found in the sixth row and three dust viruses are found in the fifth to seventh rows each found in one row. Half-frozen viruses can be found in the first two columns and rows #2 and #10. The aforementioned rows of half-frozen viruses and floatie viruses each has a shell. Hidden viruses are found in the Brick Blocks in the seventh column except for the one in the middle. Prior to version 2.0.0, the stage layout was different. The following changes were made: Capsule amount is increased from 37 to 41. The half-frozen viruses in the third column are no longer frozen. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 41 to 33. The first viruses in row #2 and #10 are replaced with shells. Moreover, the other viruses in those rows are changed to become half-frozen. A shell is added to the leftmost of row #6. The first and last Brick Blocks in column #8 are replaced with viruses, and both the Brick Block in column #6 and first virus in row #6 are replaced with floatie viruses.
	Stage 132	Dr. Toadette Dr. Iggy	Starting with 33 capsules, the objective of this stage is to eliminate all viruses (5). This stage is shaped like a clock pointing to 8 o'clock, with the hands formed by dust viruses all containing floatie viruses. The capsule amount is increased from 27 to 33 since March 18, 2021. Besides that, this stage is otherwise the same.
	Stage 133	Dr. Fire Peach Dr. Kamek	Starting with 38 capsules, the objective of this stage is to eliminate all viruses (41). In this stage, viruses (normal, caged and half-frozen) and a few dust viruses are found in the odd-numbered columns, with floatie viruses inside bubbles found in the even-numbered columns. The second Brick Block in column #2 contains a hidden lock block, and the lock block in the rightmost column is fully-frozen. The lock block in the middle column is locked behind a cage. A pop cannon is found in one of the cages in the middle column. The capsule amount is increased from 40 to 42 since version 2.0.0. Besides that, this stage is otherwise the same. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 42 to 38. All Empty Blocks are replaced with Brick Blocks. A Brick Block is added in the second column of the second row. The contents of the bottom-most cage in the middle column is changed from a virus to a pop cannon.
	Stage 134	Dr. Fire Rosalina Dr. Fire Peach	Starting with 38 capsules, the objective of this stage is to eliminate all viruses (57). The only colors available in this stage are red and green. In this stage, there are viruses in bubbles and hidden viruses in all the Brick Blocks. Exploders are found in the middle column and the topmost row, and a shell is found in the topmost row at the middle column. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 40 to 38. The available colors are changed to red and green only.
	Stage 135	Dr. Wario Dr. Wendy	Starting with 36 capsules, the objective of this stage is to collect all coins from Coin Blocks (30) and collect all virus coins (4). The only colors available in this stage are red and light-blue. In this stage, floatie viruses are surrounded by viruses in a "+" pattern, and each group has a virus coin behind them. Additional floatie viruses are arranged in three columns below the bottom-most row of Brick Blocks. All Brick Blocks in this stage contain coins. In between a few of those Brick Blocks are exploders. Prior to version 2.0.0, the stage layout was different. The following changes were made: Capsule amount is reduced from 40 to 38. The viruses below the bottom-most row of Brick Blocks are changed from two floatie viruses each surrounded to three viruses to three columns of two viruses. Prior to March 18, 2021, the stage layout was different. The following changes were made: This stage is no longer labeled as "Hard". Capsule amount is reduced from 38 to 36. The objective of this stage is changed to require collecting all virus coins in addition to collecting all coins from Coin Blocks. The available colors are changed to red and light-blue only. Virus coins are added behind each of the floatie viruses and its surrounding viruses at the topmost and middle portions of the stage. Exploders are added in the second and eighth spaces in both row #4 and #8. The viruses in row #9 and #10 are replaced with floatie viruses.
	Stage 136	Dr. Waluigi Dr. Yoshi	Starting with 35 capsules, the objective of this stage is to eliminate all viruses (35). The only colors available in this stage are red and green. In this stage, there are three groups of viruses in mirrored "L" patterns containing dust viruses and viruses inside bubbles, and a group of fully-frozen four viruses in the top-left corner. At each group's bottom-right corner, a mirrored "L" pattern of Brick Blocks separate them. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 45 to 35. The available colors are changed to red and green only.
	Stage 137	Dr. Luigi Dr. Toad	Starting with 40 capsules, the objective of this stage is to eliminate all viruses (43). This stage is shaped like a percentage (%) symbol. The Brick Blocks contain hidden viruses in all but three of them, where they contain hidden exploders in the second one in row #7, the first one in row #9 and the second one in row #3. In the middle are lock blocks that will unlock the circle portions of the percentage symbol. Some viruses are fully-frozen. The capsule amount is increased from 39 to 46 since version 1.3.5. Besides that, this stage is otherwise the same. Prior to version 2.0.0, the stage layout was different. The following changes were made: Capsule amount is reduced from 46 to 45. The two rings of cages are filled with viruses contained in red cages, with their corresponding lock block in the top-right corner. Two of the viruses are no longer fully-frozen. One of the viruses is no longer hidden in Brick Blocks. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 45 to 40. The red lock block is removed, and the cages that were originally red were changed to green at the top-left and light-blue at the bottom-right. The contents of 4 cages that were originally red (2 at the top-left, 2 at the bottom-right) are changed from viruses to exploders. The green and light-blue cages swap colors. Brick Blocks containing hidden exploders are added in the third space in row #9 and the eighth space in row #3. The contents of the Brick Block in the middle of row #7 is changed from a virus to an exploder.
	Stage 138	Dr. Bowser Dr. Waluigi	Starting with 30 capsules, the objective of this stage is to eliminate all viruses (41). The only color available in this stage is red. In this stage, the top two rows has columns of fully-frozen viruses in between Brick Blocks, while the bottom two rows contain viruses inside bubbles initially in between dust viruses. Between them are three rows of five viruses (two of them fully-frozen) between Empty Blocks, arranged in a cascade fashion. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 49 to 30. The available color is changed to red only. The dust viruses in the two topmost rows are changed to become fully-frozen viruses. The half-frozen viruses within rows #4 to #6 are changed to become fully-frozen. Shells replaced the objects directly left of the leftmost viruses within rows #4 to #6. All Empty Blocks are replaced with Brick Blocks.
	Stage 139	Dr. Waluigi Dr. Baby Mario	Starting with 37 capsules, the objective of this stage is to eliminate all viruses (28). In this stage, there is an outer ring of Brick Blocks where dust viruses are found in the corners and hidden viruses are found in the center of each of the sides. There is another ring containing Brick Blocks, in which viruses are also found in the center of each side, two of them hidden in Brick Blocks. Between the two rings are floatie viruses in the corners and dust viruses on the center of each side, and on the inside of the inner ring, there are more dust viruses with an exploder in the middle. Prior to March 18, 2021, the stage layout was different. The following changes were made: All Empty Blocks are replaced with Brick Blocks. An exploder is added in the middle of row #5.
	Stage 140 (Hard)	Dr. Koopa Troopa Dr. Bowser	The last stage of the first area and starting with 49 capsules, the objective of this stage is to eliminate all viruses (37). In the beginning of this stage, there are five dust viruses: two floatie viruses at the sides and three regular viruses in the others, along with three viruses below the row containing two dust viruses. Five more viruses including a dust virus are surrounded by Brick Blocks, and the Brick Blocks initially found in the third row contain hidden viruses. After the stage scrolled up far enough, there are viruses in cages with hidden viruses in Brick Blocks found to the left and below of the group. The lock block is hidden in the Brick Block in the third row at the seventh column after the stage scrolled up all the way. This stage will scroll for one line each time enough objects are cleared or enough capsules are added to the stage and will stop after 5 lines are introduced. When cleared, the rest of the first area in the world map gets cleared of viruses. Players also obtain 500 coins upon completing this stage. Prior to version 1.3.5, the stage layout was different. The following changes were made: Two viruses are added in the second row from top after the stage scrolled up all the way, in the rightmost two columns. Prior to version 2.0.0, the stage layout was different. The following changes were made: The four Empty Blocks at the beginning of the stage are changed to Brick Blocks. The bottom-most row of Brick Blocks are removed. The bottom-most floatie viruses covered in dust are shifted one row above, while the other two floatie viruses are no longer covered in dust. Three of the viruses at the beginning of the stage are changed to dust viruses.

Area 2

Image	Stage	Best Doctors	Overview
	Stage 141	Dr. Bowser Dr. Ludwig	Starting with 30 capsules, the objective of this stage is to eliminate all viruses (43) and destroy all Brick Blocks (28). The only colors available in this stage are red and green. In this stage, a spiral of viruses (some half-frozen) and a spiral of half-frozen Brick Blocks are intertwined, with an exploder at the end of the spiral of viruses. Prior to version 2.0.0, the stage layout was different. The following changes were made: Capsule amount is reduced from 36 to 35. The first row of Brick Blocks are arranged so that instead of occupying the odd-numbered columns, it occupies the entire row except for the leftmost, middle and rightmost columns. The second and fourth Empty Blocks in the tenth row are changed to Brick Blocks. Since March 18 2021, this stage is revamped, and the capsule amount is reduced from 35 to 30. Initially in this stage, green cages are arranged in a spiral, with its corresponding lock block between one of the Brick Blocks between the spiral. Every Brick Block except for the ones in the first row, the eighth row and the tenth row contains hidden viruses.
	Stage 142	Dr. Fire Mario Dr. Yoshi	Starting with 28 capsules, the objective of this stage is to eliminate all viruses (34). In this stage, a column of shells is in the same row as Brick Blocks, along with an exploder below one of the shells. The column of Brick Blocks next to the shells contain hidden exploders, and after all the Brick Blocks are destroyed, some floatie viruses and a formation of viruses in the shape of a moon are revealed. Above and below the formation, there are viruses and floatie viruses covered in dust clouds. Prior to March 18, 2021, the stage layout was different. The following changes were made: The dust clouds containing Empty Blocks in row #10 are removed. The contents of the middle two dust clouds in row #1 are changed from Empty Blocks to viruses.
	Stage 143	Dr. Yoshi Dr. Daisy	Starting with 36 capsules, the objective of this stage is to eliminate all viruses (29). This stage is shaped like a cross, where the viruses are locked behind cages. The lock blocks which are half-frozen are found near the corners, and there are floatie viruses near the other corners. Two of the cages in row #5 have exploders, while one in the middle column has a pop cannon. The Brick Blocks in rows #4 and #6 each contain hidden viruses and a shell. Prior to version 1.3.5, the stage layout was different. The following changes were made: Capsule amount is increased from 40 to 43. Floatie viruses are half-frozen instead of fully-frozen. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 43 to 36. The position of the green lock block and the floatie virus in the same column are swapped. The lock blocks are changed to become half-frozen while the floatie viruses are changed to become normal. An exploder is added in the top-right corner and the middle of row #5. All Empty Blocks are replaced with Brick Blocks, in which they contain hidden viruses, except the last one which contain a hidden shell. The contents of the second and second-last cages in row #5 are changed from viruses to exploders, while the contents of the cage in row #7 is changed from a virus to a pop cannon. The contents of the second Brick Block in row #6 is changed from a virus to a shell.
	Stage 144	Dr. Baby Luigi Dr. Waluigi	Starting with 35 capsules, the objective of this stage is to eliminate all viruses (38). In this stage, there are some viruses that are fully-frozen and one that is half-frozen, along with some dust viruses. Exploders are located in a "+" pattern near the bottom. Prior to March 18, 2021, the stage layout was different. The following changes were made: The Empty Blocks in the top-left corner, top-right corner and in row #10 are removed, while the others are replaced with Brick Blocks.
	Stage 145	Dr. Baby Peach Dr. Diddy Kong	Starting with 20 capsules, the objective of this stage is to collect all purple coins (13). This stage introduces caged coins, which are purple coins that are locked behind cages. Caged coins are unlocked in a sequence of groups, which require the currently-unlocked purple coins to be collected first. Most of the purple coins are found between viruses, and one of them is between half-frozen Brick Blocks. Purple coins are unlocked in the following sequence: The 3 coins in row #8. The 3 coins in column #2. The 3 coins in column #8. The 3 coins in row #2. The 1 coin in the middle surrounded by the half-frozen Brick Blocks.
	Stage 146	Dr. Boo Dr. Daisy	Starting with 38 capsules, the objective of this stage is to eliminate all viruses (23) and collect all purple coins (40). The only colors available in this stage are red and green. In this stage, there are five groups of purple coins (caged and uncaged), with the groups placed in a cross pattern. Within each group of purple coins is an exploder. In between the groups are groups of viruses which include floatie viruses arranged in two rows, with one of the groups containing a shell. Purple coins are unlocked in the following sequence: The 16 coins within rows #7 to #9. The 24 coins within rows #1 to #6. The capsule amount is increased from 38 to 40 since version 1.3.5. Besides that, this stage is otherwise the same. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 40 to 38. The objective of this stage is changed to require collecting all purple coins in addition to eliminating all viruses. The available colors are changed to red and green only. All caged Brick Blocks are replaced with purple coins (caged and uncaged). The lock blocks in row #4 are replaced with floatie viruses. Exploders are added in the middle of all the rings of cages-turned-coins (the top-right ring original had a lock block. The viruses in between the bottom two rings of purple coins are rearranged from two rows of 3 viruses (each with 2 floatie viruses and 1 regular virus) to three columns of two where the middle column has a regular virus and a shell that is in between two columns of 2 floatie viruses.
	Stage 147	Dr. Wendy Dr. Fire Peach	Starting with 32 capsules, the objective of this stage is to eliminate all viruses (27). In this stage, there is a ring of viruses inside bubbles surrounding Brick Blocks with another virus in the bubble in the middle, and that ring is surrounded by Brick Blocks with two spaces open. On the outside, there are more viruses and dust viruses, where they are in the path of either pop cannons or shells. Prior to version 2.0.0, the stage layout was different. The following changes were made: Capsule amount is reduced from 43 to 40. Four of the viruses along the sides are no longer covered in dust, while the virus in the middle is covered in a bubble instead of dust. The Brick Blocks diagonally adjacent to the middle virus no longer contain hidden viruses. The viruses in the third and seventh columns are no longer inside bubbles. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 40 to 32. All Empty Blocks are replaced with Brick Blocks. The 2 viruses in row #8 are replaced with a pop cannon and a shell respectively. A shell is added in the top-left corner and a pop cannon is added in the top-right corner. The middle 3 viruses in both column #3 and #7 are changed to be bubbles containing viruses.
	Stage 148	Dr. Koopa Troopa Dr. Wendy	Starting with 38 capsules, the objective of this stage is to eliminate all viruses (29). The only colors available in this stage are red and light-blue. In this stage, there is a path of Brick Blocks swerving around columns of Empty Blocks, with a few viruses below the Brick Blocks. Some of the Brick Blocks have hidden pop cannons. Hidden viruses are found behind the following Brick Blocks: All Brick Blocks in columns #1, #4, #6 and #8 contain viruses. Brick Blocks #1, #2 and #5 in column #3 contain viruses while #3 contains a pop cannon. Brick Blocks #3 and #4 in column #5 contain viruses, #2 contains an exploder and #6 contains a pop cannon. The bottom-most 6 Brick Blocks in column #7 contain viruses. Brick Blocks #3, #4 and #7 in column #9 contain viruses while #5 contains a pop cannon. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 55 to 38. The available colors are changed to red and light-blue only. The first 3 Brick Blocks in row #1 are changed to Empty Blocks. The rightmost Brick Block in row #4 is replaced with a virus. The contents of the second Brick Block in row #4, along with the third and the last Brick Blocks in row #6 are changed from viruses to pop cannons. The contents of the middle Brick Block in row #2 is changed from a virus to an exploder. The following Brick Blocks have viruses added inside them: (1) second and third Brick Blocks in row #3, (2) the fourth and fifth Brick Blocks in row #5, (3) the fourth Brick Block in row #7. Whereas, the contents of the fifth Brick Block in row #7 is changed so that the virus is removed from it.
	Stage 149	Dr. Bowser Dr. Baby Peach	Starting with 38 capsules, the objective of this stage is to eliminate all viruses (53). The only colors available in this stage are red and light-blue. In this stage, there are fully-frozen viruses along the sides of the square formation, with Brick Blocks forming a diamond inside surrounded by viruses. Within this formation, there are two exploders and shells. The capsule amount is increased from 45 to 50 since version 1.3.5. Besides that, this stage is otherwise the same. Prior to March 18, 2021, the stage layout was different. The following changes were made: This stage is no longer labeled as "Hard". Capsule amount is reduced from 50 to 38. The available colors are changed to red and light-blue only. The objects in row #10 are removed. The Empty Blocks within the 5 topmost rows are replaced with Brick Blocks while Brick Blocks are added within the open space surrounded by viruses. The second and second-last objects in rows #2 and #8 are replaced with exploders, while the middle viruses in row #2 and #9 are replaced with a shell and an exploder respectively. The Brick Blocks and Empty Blocks that remained (besides the aforementioned ones) are replaced with viruses. In addition to the original 2 fully-frozen viruses in row #6, 26 of the viruses are changed to become fully-frozen, most of which are around the borders.
	Stage 150	Dr. Baby Mario Dr. Blooper	Starting with 35 capsules, the objective of this stage is to collect all purple coins (19). In this stage, the coins and viruses are in a symmetrical pattern, where each side has coins, Brick Blocks, Empty Blocks and viruses (regular, inside bubbles, fully-frozen and dust viruses) are on each side. Purple coins are unlocked in the following sequence: The 6 coins in row #9. The 1 coin hidden in dust cloud in the middle column. The first 2 coins in row #7. The last 2 coins in row #7. The 4 coins found on the left side in rows #2 and #3. The 4 coins found on the right side in rows #2 and #3. Prior to version 1.3.5, the stage layout was different. The following changes were made: Capsule amount is increased from 30 to 33. Two Empty Blocks in the fifth row are changed to Brick Blocks. The capsule amount is increased from 33 to 35 since version 2.1.0. Besides that, this stage is otherwise the same.
	Stage 151	Dr. Luma Dr. Kamek	Starting with 20 capsules, the objective of this stage is to eliminate all viruses (28). The only colors available in this stage are red and green. This stage is shaped like an "S" and is formed by Brick Blocks all containing hidden viruses, exploders and viruses. The red viruses are fully-frozen while the green viruses are half-frozen.
	Stage 152	Dr. Iggy Dr. Fire Mario	Starting with 35 capsules, the objective of this stage is to eliminate all viruses (16). In this stage, two groups of viruses in the shape of an "H" are found in the middle three columns, in which the ones in the middle column are dust clouds containing shells and the viruses closer to the middle row are fully-frozen. Additional viruses are found in the second and eighth columns surrounded by Brick Blocks and Empty Blocks where the bottom ones are inside bubbles while the top ones are not. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 44 to 35. The Empty Blocks within rows #6 to #8 are replaced with Brick Blocks. The floatie virus in row #3 is swapped with the normal virus in row #5. All fully-frozen viruses are changed to become half-frozen. In addition, the viruses in row #6 are changed to become half-frozen. The contents of the dust clouds are changed from viruses to shells.
	Stage 153	Dr. Lakitu Dr. Fire Peach	Starting with 34 capsules, the objective of this stage is to eliminate all viruses (46). The only colors available in this stage are red and green. This stage is shaped like an "O" where the viruses on the leftmost and rightmost columns are half-frozen. In the middle of the stage is a skill charger. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 44 to 34. The available colors are changed to red and green only. The row of Empty Blocks in the topmost is removed, and all objects below it are moved up one row.
	Stage 154	Dr. Luigi Dr. Peach	Starting with 43 capsules, the objective of this stage is to eliminate all viruses (32). In this stage, cages are lined up vertically in broken lines parted by dust viruses containing floatie viruses and exploders. A lock block is found in the eighth column, and another lock block is found inside a cage in the second column. Prior to March 18, 2021, the stage layout was different. The following changes were made: The objects in row #10 are removed. The Empty Block in row #9 is replaced with a Brick Block. The floatie virus in row #3 is changed from being covered in dust to being in a red cage. A dust virus is added in the second space of row #2 which contains a floatie virus.
	Stage 155	Dr. Daisy Dr. Peach	Starting with 33 capsules, the objective of this stage is to collect all purple coins (16). In this stage, rows containing purple coins are between rows containing viruses in cages. On the leftmost and rightmost columns, there are fully-frozen lock blocks and a virus. Purple coins are unlocked in the following sequence: The 5 coins in row #8. The 3 coins in row #6. The 5 coins in row #4. The 3 coins in row #2. The capsule amount is increased from 28 to 33 since version 1.3.5. Besides that, this stage is otherwise the same.
	Stage 156	Dr. Luigi Dr. Baby Peach	Starting with 38 capsules, the objective of this stage is to eliminate all viruses (26). This stage is shaped like a butterfly. In this stage, there is a shell in the same row as the lock blocks, which will unlock the cages in the rows above them. Besides that, there are viruses inside bubbles below that row and a couple of dust viruses in the third row.
	Stage 157	Dr. Donkey Kong Dr. Bowser	Starting with 38 capsules, the objective of this stage is to eliminate all viruses (40). In this stage, the corners contain two groups of viruses locked behind cages and another two groups that are half-frozen. Each of those groups have two exploders. A lock block and eight viruses are partially surrounded by Brick Blocks in the middle, all within bubbles. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 53 to 38. The contents of the first two cages in row #2 and the last two cages in row #8 are changed from viruses to exploders. The last two viruses in row #2 and the first two viruses in row #8 are replaced with exploders, which are also half-frozen.
	Stage 158	Dr. Daisy Dr. Boo	Starting with 36 capsules, the objective of this stage is to eliminate all viruses (32). The only colors available in this stage are red and green. In this stage, there are three rings of cages that locked Brick Blocks and in the case of the middle ring of cages, a few viruses. In the middle of the left and right ring of cages, there are viruses inside bubbles, while viruses and a pop cannon are is in the middle ring. Two other lock blocks are half-frozen among the like-colored half-frozen viruses. A shell is located in row #10 alongside Brick Blocks. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 49 to 36. The available colors are changed to red and green only. The light-blue lock block is replaced with a pop cannon. The middle Empty Block in row #10 is replaced with a shell, while all other Empty Blocks are replaced with Brick Blocks (even the ones inside cages). 2 viruses are added in the gaps in the topmost row.
	Stage 159	Dr. Luigi Dr. Toad	Starting with 38 capsules, the objective of this stage is to eliminate all viruses (40). The only colors available in this stage are red and light-blue. In this stage, there are two columns of viruses behind cages, some with floatie viruses. The lock block is fully-frozen and is found among viruses in a formation of a hat. Additional viruses are hidden in the Brick Blocks in the fourth and sixth columns, except the ones in the topmost row. A pop cannon is located in the middle column. Prior to version 1.2.0, the stage layout was different. The following changes were made: Capsule amount is increased from 40 to 46. The viruses in the eighth row are no longer hidden in Brick Blocks. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 46 to 38. The available colors are changed to red and light-blue only. A pop cannon is added in the gap in row #7.
	Stage 160 (Hard)	Dr. Toad Dr. Bowser Jr.	In the final stage of this world and starting with 42 capsules, the objective is to eliminate all viruses (53). In this beginning, there are three columns of three viruses inside bubbles in the middle, with Brick Blocks next to them in the fifth row. The other viruses are between Brick Blocks, and within the Brick Blocks in row #3 are a pop cannon and an exploder respectively. A shell is located in the first row before the stage scrolls. As the stage scrolls, half-frozen viruses and viruses inside bubbles appear in addition to the regular viruses, as well as shells and exploders. This stage will scroll for one line each time enough objects are cleared or enough capsules are added to the stage and will stop after 7 lines are introduced. Once it is cleared, the remaining area of the stage map gets cleared of viruses, and players can access World 5. Upon completion, players earn a free Staff Ticket. Prior to version 1.2.0, the stage layout was different. The following changes were made: Capsule amount is increased from 48 to 55. In the beginning before the stage scrolls, the fifth row has a shell in the rightmost column instead of a Brick Block. Prior to version 2.0.0, the stage layout was different. The following changes were made: In the beginning before the stage scrolls, Brick Blocks are added to the even-numbered columns in the fifth row. In the beginning before the stage scrolls, the shell is removed from the fifth row. Prior to March 18, 2021, the stage layout was different. The following changes were made: Capsule amount is reduced from 55 to 42. In the beginning of the stage, the viruses in columns #3, #5 and #7 are changed to become inside bubbles, and are changed to have matching colors within the column. Viruses are added in the second and second-last spaces in row #2 and #3. The last Brick Blocks in row #1 and the first-revealed row are replaced with a shell. The second Brick Blocks in the second-revealed row and the fourth-revealed row are replaced with exploders. The first and last Brick Blocks in the third-revealed row are replaced with a shell and an exploder respectively. The Brick Blocks in row #3 now contain a pop cannon and an exploder respectively. A shell is added in the last Brick Block in the seventh-revealed row. The last three revealed rows are removed, including the topmost row of Empty Blocks, rendering the stage with only 7 rows to scroll through instead of 10.

Challenge stages

Image	Stage	Best Doctors	Overview
	Stage 4A	Dr. Wendy Dr. Bowser	Within an 80 second time limit, the objective of this stage is to eliminate all viruses (20) and collect all purple coins (16). In this stage, there are four rows of purple coins (both caged and uncaged) with Brick Blocks between them, along with rows of viruses between those rows where they are between the Brick Blocks. Viruses are hidden in the topmost row of Brick Blocks. Purple coins are unlocked in the following sequence: The 4 coins in row #8. The 4 coins in row #6. The 4 coins in row #4. The 4 coins in row #2. The timer is increased from 52 seconds to 80 seconds since version 2.0.0. Besides that, this stage is otherwise the same. Starting from version 1.2.0, completing this stage awards the player 500 coins.
	Stage 4B	Dr. Toad Dr. Dry Bowser	Within a 105 second time limit, the objective of this stage is to eliminate all viruses (39). In this stage, two rows of viruses are locked behind cages, and in between the rows, the corresponding lock blocks are found among dust viruses (some contain floatie viruses). Prior to version 2.0.0, the stage layout was different. The following changes were made: Two dust viruses next to lock blocks are changed to regular viruses of the same color as the lock blocks. Certain dust viruses are changed from floatie viruses to regular viruses. Starting from version 1.2.0, completing this stage awards the player 500 coins.
	Stage 4C	Dr. Fire Rosalina Dr. Wendy	Within a 97 second time limit, the objective of this stage is to eliminate all viruses (41). This stage is shaped like the letter "Z" where one group consists of regular viruses, one group consists of viruses inside bubbles and another group has Brick Blocks. Among the Brick Blocks, one diagonal line of them are fully-frozen, another consists of hidden viruses and floatie viruses, while another line do not contain anything. Prior to version 2.0.0, the stage layout was different. The following changes were made: Timer is increased from 75 seconds to 97 seconds. Within Brick Blocks, a number of hidden floatie viruses are changed to hidden regular viruses. Completing this stage awards the player 1000 coins and a Staff Ticket (3 Hearts prior to version 1.2.0).

Special Stage

Image	Stage	Best Doctors	Overview
	Special Stage	Dr. Yoshi Dr. Wario	Starting with 51 capsules, the objective of this stage is to eliminate all viruses (51). In the beginning, there are five columns of cages with Empty Blocks in between containing floatie viruses in the middle column, one lock block in the rightmost column and viruses in the other spots. The bottom-most row of Brick Blocks contain hidden viruses, while the Brick Blocks in the row above the cages do not. Additional floatie viruses appear when the stage scrolls up once, and in the three rows after that, more viruses and Brick Blocks each containing hidden viruses appear. This stage will scroll for one line each time enough objects are cleared or enough capsules are added to the stage and will stop after 4 lines are introduced. Completing this stage awards the player 1000 coins and Dr. Luigi. Prior to version 2.2.0, the stage layout was different. The following changes were being made since: The Empty Blocks in row #6 are changed to Brick Blocks. The row of Empty Blocks are removed from the topmost row, rendering the stage with only 4 rows to scroll through instead of 5.

Stage layouts for scrolling stages

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  Stage 100 (all 5 lines)

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  Stage 120 (all 7 lines)

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  Special Stage (all 4 lines)

Stage layouts in previous versions

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  Stage 159 prior to version 1.2.0

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  Stage 160 prior to version 1.2.0

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  Stage 140 prior to version 1.3.5. Note the number of viruses required to be eliminated.

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  Stage 143 prior to version 1.3.5

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  Stage 150 prior to version 1.3.5

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  Stage 131 prior to version 2.0.0

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  Stage 135 prior to version 2.0.0

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  Stage 137 prior to version 2.0.0

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  Stage 140 prior to version 2.0.0

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  Stage 141 prior to version 2.0.0

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  Stage 147 prior to version 2.0.0

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  Stage 160 prior to version 2.0.0

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  Stage 4B prior to version 2.0.0

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  Special Stage prior to version 2.2.0

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  Stage 122 prior to March 18, 2021

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  Stage 123 prior to March 18, 2021

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  Stage 126 prior to March 18, 2021

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  Stage 127 prior to March 18, 2021

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  Stage 128 prior to March 18, 2021

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  Stage 129 prior to March 18, 2021

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  Stage 130 prior to March 18, 2021

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  Stage 131 prior to March 18, 2021

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  Stage 132 prior to March 18, 2021

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  Stage 133 prior to March 18, 2021

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  Stage 134 prior to March 18, 2021

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  Stage 135 prior to March 18, 2021

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  Stage 136 prior to March 18, 2021

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  Stage 137 prior to March 18, 2021

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  Stage 138 prior to March 18, 2021

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  Stage 139 prior to March 18, 2021

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  Stage 141 prior to March 18, 2021

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  Stage 142 prior to March 18, 2021

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  Stage 143 prior to March 18, 2021

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  Stage 144 prior to March 18, 2021

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  Stage 146 prior to March 18, 2021

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  Stage 147 prior to March 18, 2021

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  Stage 148 prior to March 18, 2021

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  Stage 149 prior to March 18, 2021

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  Stage 152 prior to March 18, 2021

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  Stage 153 prior to March 18, 2021

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  Stage 154 prior to March 18, 2021

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  Stage 157 prior to March 18, 2021

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  Stage 158 prior to March 18, 2021

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  Stage 159 prior to March 18, 2021

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  Stage 160 prior to March 18, 2021