Note: This game is also titled Mario And Luigi RPG 3!!!.

Enter the Lumbar Nook, and dig into the broken bone. Press A, B, X, Y, L, R, Y, X, B, A to have the alarm ring instantly.

Successfully complete the game with Mario, Luigi, and Bowser over level 40 to view an alternate ending. Successfully complete the game with Mario or Luigi below level 18 to view another alternate ending.

Get an "A" rank in the indicated challenge to unlock the corresponding item:

Advice Patch: Spin Pipe
Bro Socks: Yoo Who Cannon
Challenge Medal: Green Shell
Daredevil Boots: Jump Helmet
Dizzy Boots: Super Bouncer
Master Wear: All challenges
Siphon Gloves: Magic Window

Get an "A" rank in the indicated challenge to unlock the corresponding item:

Bone Fangs: Koopa Corps
Furry Band: Bob-omb
Heroic Ring: Magikoopa
King Shell: All challenges
Treasure Ring: Goomba Storm