Cheats
While paused press the following codes:

All Items Mapped	Triangle, Triangle, L2, R2, L2, R2, R1, Circle
All Weapons, Lots of Ammo and All Keys	X, Triangle, L1, Up, Down, R2, Left, Left
Full Map	Triangle, Triangle, L2, R2, L2, R2, R1, Square
God Mode	Down, L2, Square, R1, Right, L1, Left, Circle
Skip Current Level	Right, Left, R2, R1, Triangle, L1, Circle, X
Transparent Walls	L1, R2, L2, R1, Right, Triangle, X, Right

Final Level Password
Final Level - CRMSKZX9Z1