Killzone (PS2)

Cheat mode:
Start a new game and enter Shooterman as a case-sensitive name. All levels and characters will be unlocked.

One shot kill:
Hold L1 at any menu screen, then press Circle, Triangle, Circle, Triangle, X. This code may not work on all levels.

All movies:
Hold L1 at any menu screen, then press Circle, Square, Triangle, Circle, Square.

Big head enemies:
Hold L1 at any menu screen, then press Circle, Square, X, Circle, Circle.

Control character selection screen:
Press Left Analog-stick Left and Left Analog-stick Right at the character selection screen to move the portraits in the corresponding direction.

Play as Luger:
Successfully complete mission 2 in story mode.

Play as Rico:
Successfully complete mission 3 in story mode.

Play as Hakha:
Successfully complete mission 4 in story mode.