Do the following trick at the Game Start/Options screen. Press and hold R1, and press Up, Right, Down, Left, Up, Right, Down, Left and Up.
Auto rapid fire mode
Do the following trick at the Game Start/Options screen. Press and hold L1, and press Triangle, O, X, Square, Triangle, O, X, Square and Triangle.
Nine Credits
Do the following trick at the Game Start/Options screen. Press and hold L1+R1 and press Triangle, Square, X, O, Triangle, Up, Left, Down, Right and Up.