Blooper's Secret Lair

Blooper's Secret Lair, or , is the secret level for Acorn Plains in New Super Mario Bros. U. One of the game's few underwater courses, the level is, as stated, filled with Bloopers. The player must have found the secret exit in Tilted Tunnel to reach this course. Completion of this level skips Layer-Cake Desert, Sparkling Waters, and Frosted Glacier, and provides access to Soda Jungle, bypassing The Mighty Cannonship.

Layout
This course has many Warp Pipe, most of which either pump a current that forces the player in a certain direction or expel Bloopers. Many of the pipes that expel water rotate, in places requiring the player to wait for this to happen to be able to continue or forcing them to take a longer path rather than what would be a shortcut. Many coins in bubbles litter the course.

Star Coins

 * Star Coin 1: In a high up alcove just past the second ? Block containing a Fire Flower.
 * Star Coin 2: In what looks to be a closed off area at first. The player can reach the coin by swimming under the red pipe beside it, under the portion of the screen the camera shows.
 * Star Coin 3: Through a Warp Pipe in the area with many rotating pipes that pump out water. This secret room also contains a pair of Blooper Nannies guarding the Star Coin.

Enemies

 * Bloopers
 * Blooper Nannies
 * Blooper Babies

Names in other languages
Blooper-Beschuss!