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.
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.