World 6-6 (New Super Mario Bros. Wii)

This level takes place in a dark underground cavern. There is a boat with a light that the player can move by rotating the Wii Remote. Various enemies, such as Piranha Plants, Cheep-Cheeps, Swoopers, and Fire Bros., make an appearance here. The water may rise or lower at some points of the level.

A secret exit exists in this level which can be found by entering a red pipe in the area with Fire Bros. The player will be in an area with a Glow Block along with a Swooper swarm. After that area is the secret flagpole. This unlocks a Warp Cannon which takes the player to World 8. Players can run through this level with a Mini Mushroom by dashing across the water.

Enemies

 * Cheep-Cheeps
 * Mega Cheep-Cheeps
 * Piranha Plants
 * Swoopers
 * Fire Bros.