All Cheats:
Enter the cheats screen and press L1, L2, R2, R1, L1, L2, R2, R1, L1, L2, R2, R1, L1, L2, R2, R1,
Circle, Circle, Circle, Circle, X, X, X, X, Square, Square, Square, Square,
Select, Select, Select, Select. This code will unlock allandd every code.

Invincibility:
Enter the cheats screen and press L1, Square, Circle, Circle, Square, L1, L2.

Max Armor:
Enter the cheats screen and press L1, L1, R1, R1, X, X, Circle, Circle.

Level Select:
Enter the cheats screen and press Circle, X, Square, Square, X, Square, Circle.

All Weapons:
Enter the cheats screen and press R2, X, L1, Square, R1, Circle, L2.

Endless Ammo:
Enter the cheats screen and press L2, Circle, R2, Square, Circle, L2, R1.

Max Ego:
Enter the cheats screen and press R1, R1, Circle, Circle, L1, L1, R2.

Big Head Mode:
Enter the cheats screen and press Square, Square, X, Circle, Circle, X, Square.