Push start to pause the game and then give the follewing combinations to activate the cheats.
Big guns:
square ( 4 times ), circle ( 2 times )
Missile crossbow:
right, right, left, left, L2, L2, R2, R2, circle, circle, square, square
Missile sniper:
square, left, right, L2, R2, right, square, R2, R2, L2, left, left
Explosive crossbow:
left, right, right, left, square, circle, L2, R2, square, circle, left, right
Explosive sniper:
L2, R2, right, right, left, left, right, right, R2, L2, square, circle
One hit kills:
circle, left, right, right, left, circle, L2, R2, circle, square, square
Ulimited ammo:
square, circle, square, circle, square, circle, square, circle, left, square, circle, square, circle, square
Unlimited TOC:
circle, circle, square, square, left, right, right, left, L2, R2, L2
Unlimited spycam:
left, left, right, right, R2, R2, L2, L2, square, square, circle, circle
50% damage:
square, square, circle, circle, left, left, right, right, circle, circle, square, square
No damage done by bullets:
left, right, right, left, square, circle, circle, square
Skip level:
L2, square, L2, circle, L2, left, L2, right, L2, R2, R2, square, R2, circle, R2, left, R2, right, square
complete bank level:
R2, L2, square, circle, left, R2, left, left, square, circle, square
complete carmen level:
R2, L2, right, left, left, L2, R2, square ( x3), R2
complete Forsythe level:
L2, L2, left, left, left, L2, R2, square, R2, square, R2
complete installation K level:
R2, L2, square, square, left, L2, L2, square, square, L1, square
complete La Casa level:
R2, L2, right, left, left, L2, R2, square ( x3 ), R2
complete Magyar level:
R2, circle, circle, left, left, L2, R2, right, square, right, right
complete Mod level:
R2, L2, right, R2, left, circle, R2, circle, right, right, left
complete museum level:
L2, L2, right ( x3 ), L2, R2, square, R2, square, R2
complete Reliance level:
R2, L2, right, left, R2, L2, right, square, circle, square, circle
complete Silo level:
R2, L2, right, left, left, L2, circle, R2, square ( x3 )
complete training level:
left, right, right, left, circle, square, R2, L2, circle, circle, square