Big Boo Battle

Big Boo Battle is a level of Super Mario 64 DS. Upon completing it, Mario will earn the key to unlock Luigi. However, this level is deceivingly named; The boss that Mario fights appears to be King Boo, not Big Boo.

This level is actually a pocket level of Big Boo's Haunt, which is where the entrance is located. The entrance can be found in the Luigi Painting on the third floor of the mansion. Being a pocket level of Big Boo's Haunt provides Big Boo Battle a haunted house setting. It is a maze, and the goal is to find the correct path, as the wrong path (or simply falling) will warp Mario back to the start, similar to what can happen in Forever Forest in Paper Mario. To find the correct path, the player must listen to King Boo's laughter in the background, and sense which direction they should travel in. The correct path from the touch screen map would be right, top, right, top.

Star 1
Find the eight Red Coins that are spread out throughout the level. This Power Star requires Wario's help to obtain, as his strength is needed to break a black Brick Block containing a Red Coin. There will be two stars if all but the first red coin is collected, then if the player goes back to room one, they will hear the star intro sound, but see the wall. Navigate the maze again, two stars are there. The second star does not count towards the star total.

Star 2
There is a hidden Star behind the Boo portrait in the last room before the boss. However, it requires Luigi's Power Flower ability in order to reach it.