Player Invulnerability
While playing in offline mode, pause the game and input UP, UP, UP, LEFT, DOWN, DOWN, DOWN, LEFT, UP, UP, UP, LEFT, RIGHT. A sound similar to the effect you hear when you pause the game will occur. This code cannot be turned off until you shut off your game system.

Regerating Ammo
Pause while playing offline and input UP, DOWN, LEFT, DOWN, DOWN, LEFT, DOWN, DOWN, LEFT, DOWN, DOWN, DOWN, LEFT, RIGHT. A chirp similar to the one heard when pausing will occur. Your ammo counter will go down, but will refill instantly when reloading.