Enable Cheat Mode:
     Pause  game  play,  then  hold  L1 + R1 and press Circle, Circle,
Left, Triangle, Circle, X. The following codes can now be enabled.

Infinite ammo:
     Enable  Cheat  Mode  then press L2, L1, Square, L2 L1, R1. Repeat
cheat to disable.

Commit Suicide:
     Enable   Cheat  Mode  then  press  X,  Triangle,  Circle,  Right,
Triangle, Circle.

Hide HUD:
     Enable  Cheat Mode then press Circle, Down, Circle, Up, Triangle,
Circle.

Kill Enemy:
     Enable Cheat Mode then press Down, L2, L1, Up, Square. The person
you have to hunt down in various missions will be killed.

Pickup OSS Document:
     Enable Cheat Mode then press Up, X, R2, R1, Up, Square.

Disable Shellshock:
     Enable Cheat mode, then press L2, R1, L2, L1, Triangle, Triangle.