Pause game play in single player mode then press Up, Down, Left, Down, Down, Left, Down, Down, Left, Down, Down ,Down, Left, Right. A sound will confirm correct code entry. Repeat the code to disable its effect. Your ammunition will decrease, but will refill instantly after reloading.
Invincibility
Pause game play in single player mode then press Up, Up, Up, Left, Down, Down, Down, Left, Up, Up, Up, Left, Right. A sound will confirm correct code entry. This code cannot be disabled until the PSP is powered off.
Low resolution soldiers
Pause game play in single player mode then press Down, Down, Down, Up, Up, Left, Down, Down , Down, Down, Left, Up, Up, Up, Left. A sound will confirm correct code entry. Repeat the code to disable its effect.
Slow motion sounds
Pause game play in single player mode then press Up, Up, Up, Left, Up, Down, Up, Up, Left, Down, Down, Down, Left, Up, Down, Down, Left, Right. A sound will confirm correct code entry. This code cannot be disabled until the PSP is powered off.
Cheats submited by Rick on June 29, 2006