Unlockable Cheats
Beat the game to be able to unlock the following cheats. To activate the
cheats pause game-play and hold L and R buttons and press the following combinations

Restore Health:
B, B, X, X

Invicibility:
B, X, B, Up

Perfect Mode:
X, Down, Y, A

Always Devastating:
Y, Up, Y, Down

Have Upgrades:
Up, Down, Y, B

Infinite Second Weapon:
B, B, Down, X

Targeting Indicator:
Down, X, Up, B

To have access to the following cheats you must first beat the game.

To activate the cheats pause game-play and hold L + R before entering the
following codes:

Have Upgrades:
Up, Down, Y, B

Restore Health:
B, B, X, X

Perfect Mode:
X, Down, Y, A

Always Devastating:
Y, Up, Y, Down

Targeting Indicator:
Down, X, Up, B

Infinite Second Weapon:
B, B, Down, X

Invicibility:
B, X, B, Up