Unlock World 4
Defeat the Boss in the last castle of World 2 with Mini Mario to unlock World 4.

Unlock World 7
Defeat the Boss in the last castle of World 5 with Mini Mario to unlock World 7.

To play as Luigi in single player mode, hold L + R and press A when selecting a saved game file. Once loaded, you will control Luigi instead of Mario.

Unlimited Saves
During a game save, while the saved message pops up press start, this will not affect the current save and will not count towards the number of saves you have used in the game.

Unlock USA Extreme Bike
To unlock the USA Extreme Bike, on the Game Mode screen enter the code RUBBABUBBA using the D-Pad and the buttons. There is no confirmation for this, but once entered the bike will be available.

Characters for code entry:
Using the D-Pad, press Right, Up, B, B, A, B, Up, B, B, A.

Mini Arcade Shooter
The hidden arcade game can be accessed by viewing the credits all the way through, at the end you will have a chance to play the Arcade game.

*Cheats are entered during gameplay.

Bulletproof Cheat
Hold L1, then press X, R1, Triangle, R1, Square, L2.

Drain Enemy Health Cheat
Hold L1, then press Square, O, X, L2, R1, Triangle.

Infinite Assault Rifle Ammo Cheat
Hold L2, then press X, Circle, X, L1, Square, Triangle.

Infinite Grenade Launcher Ammo Cheat
Hold L2, then press L1, Triangle, R1, Circle, L1, Square.

Infinite Shotgun Ammo Cheat
Hold L2, then press R1, Circle, Square, L1, Square, X.

Infinite SMG Ammo Cheat
Hold L2, then press Circle, Triangle, L1, R1, X, Circle.

One Shot Kills Cheat
Hold L1, then press Triangle, X, Triangle, Square, L2, Circle.

Textureless Mode Cheat
Hold L1, then press L2, X, Circle, X, Triangle, R1.

Wield Excalibur Cheat
Hold L2, then press Triangle, X, O, R1, Triangle, L1.