Pause during a game, hold L2, R2 and press Up, Up, Down, Down, Left, Left, Right, Right, Square, triangle, Square, triangle, Select, and Start.
When using Max, hold the Fire button and press the Equip weapon button 4 times.
From the Main Menu, hold L2 + R2 and press Square (x2), Triangle, Square.
Pause during a game, then hold L2 + R2 and press Up, Down, Right, Left, X, Triangle, Circle, Square, Square + Start toplay as a character that is part Kurt, Max, and Doctor Hawkins.
Pause during a game, then hold L2 + R2 and press X, Circle, X, Circle.
Pause during a game, then hold L2 + R2 and press Circle, X, Circle, X.
While playing as Doctor Hawkins, press L2 + R2 + Left + X.
