World Mushroom (New Super Mario Bros. 2)

World Mushroom is the first special world in New Super Mario Bros. 2. This world has a generic design which is similar to that of World Flower and World Star. The background colour of this world is pink. It is an alternative world to World 2 and thus it is optional. This world can be accessed by completing World 1-Cannon. There are 3 Toad Houses in this world, one of each of red, green and yellow (Star) varieties.

There are 9 levels in this world and, unlike normal worlds, does not have a tower level. There is also only 3 normal levels on the main path in this world, contradictory to 5 to 6 levels in normal worlds. Levels in this world (other than World Mushroom-Rainbow and World Mushroom-Cannon) can be based on any theme. There is also a Ghost House in this world. There are also two secret levels which the players have to find the secret exits for. The world ends, as always, with the castle level, where Larry Koopa, the boss of this world, is waiting, unless the player takes the path to the cannon, which will lead to World Flower when completed, allowing the player to skip an additional two worlds, World 3 and World 4.

Mario begins on the floor of the world beside a Cannon Pipe. The overworld music here is a remix of the overworld theme in World 1. As Mario enters the Cannon Pipe, two rows of coins appear one after another above the pipe and Mario gets shot out into the sky, collecting the coins. Mario will then land on an orange moving platform. Coins will then begin spewing out from the top and bottom of the area. Three fast spinning coin rings of various sizes can then be found and collected. A large Coin Roulette Block containing 10, 50 or 100 coins can then be found. This is followed by another set of spinning coin rings and a Red Ring. The Red Coins spin along with several spinning coins which has a flower-like pattern. Collecting the 8 Red Coins replaces the player's inventory with a Gold Flower. This is followed by more coins being spewed out from the top and bottom of the area. Finally, a 100 Gold Coin will fall, marking the end of the course.

Star Coins

 * Star Coin 1: Early in the level, there will be a gold Warp Pipe, surrounded by color blocks. Mario will need to navigate through the block in order to reach the Warp Pipe. Inside, Mario will need to ground pound the POW Blocks in order to get the Star Coin.
 * Star Coin 2: After the checkpoint, the player will pass by the Red Ring. Under the Red Ring is a gold Warp Pipe. Mario will need to navigate through the block maze to reach the pipe. Inside, Mario should grab the Gold Flower inside the left ? Block. Mario can use the Gold Flower to destroy the Brick Blocks surrounding the Star Coin.
 * Star Coin 3: At the end of the level, the player will notice a red Koopa Troopa on top of some blocks. Mario will need to use the Raccoon Leaf in order to gain height and reach the high blocks with the final Star Coin.

Secret Exit
At the end of the level, the player will notice a red Koopa Troopa on top of some blocks. Mario will need to use the Raccoon Leaf in order to gain height and reach the high blocks above the Koopa. On the high left platform, there a two invisible ? Blocks. One of the blocks contains a coin, while the other has a Beanstalk. Mario will need to hit the beanstalk block and climb the beanstalk. This will lead to the secret exit, allowing the player to reach a red Toad House and World Mushroom-A.

This level is an underwater level featuring Urchins and Cheep Cheeps. This is also an auto-scrolling level.

Star Coins

 * Star Coin 1: The first Star Coin is early in the level. If the player tries to enter the alcove from the left, then the left side will close up. The player can only get this Star Coin from the right. However, Mario will need to hurry before the level auto-scrolls too far.
 * Star Coin 2: The second Star Coin is after the checkpoint. It is located in a closed alcove at the top of the screen. When Mario gets close to the Star Coin, the alcove will open up, allowing the player to reach the Star Coin.
 * Star Coin 3: Directly after the second Star Coin, there will be an Urchin blocking a green Warp Pipe at the top of the screen. Mario mush use a Fire Flower to defeat the Urchin and enter the Warp Pipe. Inside, the player will need to hurry to the top of the area, otherwise, the walls will close and the Star Coin will be inaccessible.

Star Coins

 * Star Coin 1:
 * Star Coin 2:
 * Star Coin 3: In the third area where Mario must choose a door, enter the top one. Inside, hit the middle and right-most ? Switches. This will cause the blue blocks to disappear, allowing access to the top path. In the top path, Mario must wall-jump up the second shaft. Then, he must hit the ? Switch to case the third Star Coin to appear. Mario must then backtrack and wall-jump up the first shaft. Mario can finally get the Star Coin.

Secret Exit
When Mario hits the ? Switch to reveal the third Star Coin, a door will also appear to the right. Enter the secret door to go to the Secret Exit, which leads to World Mushroom-B.

Upon completing this level, Mario will unlock the path to World Mushroom-Cannon, which will lead to World Flower.

Star Coins

 * Star Coin 1:
 * Star Coin 2:
 * Star Coin 3:

The cannon in this world will blast Mario to World Flower, allowing him to skip World 3 and World 4.

Upon completing this level, Mario will unlock the path to World Mushroom-3, allowing him to skip World Mushroom-2 and World Mushroom-Ghost House.

Star Coins

 * Star Coin 1:
 * Star Coin 2:
 * Star Coin 3:

This level is an underground level featuring Buzzy Beetles. There is also a black Warp Pipe, which will gives Mario 3 1-Up Mushrooms after shooting enough fireballs into it. This is also an auto-scrolling level.

Star Coins

 * Star Coin 1: The first Star Coin is in plain view. However, it can be tricky because it is sitting on a single Donut Lift under the black Warp Pipe. Mario must be cautious when trying to get the Star Coin.
 * Star Coin 2: After exiting the area with the checkpoint, the second Star Coin is in plain sight. Mario will need to use the platforms that go down in order to reach the second Star Coin.
 * Star Coin 3: After the second Star Coin, the third Star Coin is in clear view. Mario will need to use one of the nearby Buzzy Beetles in order to hit the POW Block, which will destroy all of the blocks around the Star Coin. Then Mario can easily grab it.

Undead Piranha Plants, Super Undead Piranha Plants and Whomps appear in this castle while getting chased by a Giant Spiked Ball.

Star Coins

 * Star Coin 1: While being chased by the Giant Spiked Ball, Mario will notice a Star Coin under 2 Brick Blocks. Ground pound the bricks as Super Mario and obtain the Star Coin.
 * Star Coin 2: At the end of the first area is a pipe to the next part of the level. If Mario ignores the pipe and goes past it, he will find the second Star Coin.
 * Star Coin 3: For the third Star Coin, the player will need to be Raccoon Mario. At the door leading to Larry Koopa, Mario can use the space to fly above the boss door and obtain the final Star Coin.