In gameplay enter the following codes using the controller in the second port. ALL codes except the clothes one must have L1 held down whilst inputing them.

Refill Ammo to Max Capacity:
Hold L1 and press Up, Up.

Unlock Full Health (Except Kissing Level):
Hold L1 and press R2, R2, R2.

Unlock ALL Weapons:
Hold L1 and press Up, Up, Up, Up

Unlock Infinite Ammo Toggle:
Hold L1 and press Up, Down, Up, Down.

Massive Money Gain:
Hold L1 and press Triangle, Square, Circle, X.

Unlock ALL Gym Grapple Moves:
Hold L1 and press Up, Left, Down, Down, Triangle, Square, X, X.

Unlock ALL Hobo Fighting Moves:
Hold L1 and press Up, Left, Down, Right, Triangle, Square, X, Circle.

Unlock ALL Clothes:
L1, L1, R1, L1, L1, L1, R1, R1