Master cheat code:
Enter Y, X, B, X, Y, A, B, A at the cheats screen under the options menu. All cheats will be unlocked.

Master option code:
Enter B, B, A, A, Y, X, Y, X at the cheats screen under the options menu. All normal game options will be unlocked.

Level select:
Enter X, Y, A, B, Y, X, A, A at the cheats screen under the options menu.

Super health:
Enter A, A, Y, B, Y, B, X at the cheats screen under the options menu.

Unlimited ammunition:
Enter Y, B, A, X, Y, X, A, B at the cheats screen under the options menu.

Unlimited grenades:
Enter X, A, X, Y, A, X, A, X at the cheats screen under the options menu.

Rapid rails:
Enter X, Y, X, Y, A, A, B, B at the cheats screen under the options menu.

Bouncy grenades:
Enter X, X, X, X, X, X, X, X at the cheats screen under the options menu.

Gibby explosions:
Enter B, X, A, Y, B, X, A, Y at the cheats screen under the options menu.

Gibby ammunition:
Enter A, A, A, A, X, Y, A, A at the cheats screen under the options menu.

Fat mode:
Enter X, X, X, X, B, A, X, X at the cheats screen under the options menu.

Directors cut:
Enter Y, A, X, B, X, A, Y, B at the cheats screen under the options menu.

Walking dead:
Enter A, A, A, A, A, A, A, A at the cheats screen under the options menu.

Wacky deaths:
Enter B, B, B, B, B, B, B, B at the cheats screen under the options menu.

Rain of fire:
Enter Y, Y, Y, Y, Y, Y, Y, Y at the cheats screen under the options menu.

Explosive personality:
Enter A at the cheats screen under the options menu. Press Use on someone and they will gib.

Joke message:
Enter Y, A, Y, A, Y, A, Y, A at the cheats screen under the options menu.