Invincibility
While playing the game, hold L1 and press X, R1, Triangle, R1, Square, L2. If you entered the code correctly, you will hear a sound.

One shot kills
While playing the game, hold L1 and press Triangle, X, Triangle, Square, L2, Circle. If you entered the code correctly, you will hear a sound.

Draw enemy health
While playing the game, hold L1 and press Square, Circle, X, L2, R1, Triangle. If you entered the code correctly, you will hear a sound.