World Mushroom-B

 is the second secret level of World Mushroom in New Super Mario Bros. 2. This level is an autoscroll level comprised of many Beanstalks and Koopa Troopas. To unlock this level, the player needs to locate the secret exit in World Mushroom-Ghost House.

Layout
First off, Mario begins on a cliff in front of Beanstalks, mushroom platforms and Koopa Troopas. Moving forward, there is a green pipe which takes the player to the main area. As Mario comes out from the pipe, the level begins autoscrolling. A Chain Chomp can be seen on the right. Above, there are Brick Blocks, ? Blocks and a red POW Block. The Brick Blocks contain Beanstalks and the ? Block on the right contains a Super Leaf. Climbing up the Beanstalk, there are several coin rings spinning around. Even more Beanstalks appear from blocks where there are several Koopa Paratroopas. A Chain Chomp can then be seen on a green mushroom platform. Going past it, there are several hidden blocks containing 1-Up Mushrooms on the right. Going further up is the Checkpoint Flag. More Beanstalks and a Super Leaf can be found. This is followed by circling Paratroopas and a Red Ring. Just after that, several Koopas and a Gold Ring can be found along with more blocks containing Beanstalks. Another Paratroopa ring can be found enclosing the third Star Coin. Further up are more Beanstalks and Chain Chomps. After that, a green pipe leading out of the area can be found. Moving right, a lone red Paratroopa can be seen, followed by the Goal Pole. Completing this level will unlock World Mushroom-Cannon.

Star Coins

 * Star Coin 1: The player should see this easily to the left of the level early on. The player just have to avoid several Paratroopas.
 * Star Coin 2: On a yellow mushroom platform on the right side of the level just before the checkpoint. Mario has to jump at the right position because if he jumps too high, he won't be able to reach it any longer as a green mushroom platform just above the Star Coin blocks the entire bottom half of the level.
 * Star Coin 3: Paratroopas can be seen enclosing this Star Coin after the checkpoint.

Enemies

 * Koopa Troopas
 * Koopa Paratroopas
 * Chain Chomps