Cheats
Press the following codes in the Main Menu to unlock the desired cheat. A sound will signal correct entry.

All Weapons	R1, L2, Square, Circle, R1, R2, L2
Immunity	Circle, Circle, L1, L2, R1, R2, Square
Invincibility (Doesn't work in Story mode)	Square, Square, L1, R1, L2, R2, R2
Unlimited Ammo	R1, R2, R1, R2, Square, Circle, Square
Unlock all Missions	L1, R1, L1, L2, Square, Square, Circle
Unlock all Vehicles	L1, L1, Square, Circle, L1, R1, Circle