All Weapons
 
For all weapons and maximum ammo, call up the 
inventory screen and press one of the following 
key sequences (depending on how you set your controls.)

Default Controls 
L1, Triangle, R2, L2, L2, R2, Circle, L1

Control Method 2 
Triangle, Circle, R2, L2, L2, R2, L1, Triangle

Control Method 3 
Triangle, R1, R2, L2, L2, R2, L1, Triangle

Level Skip 

While playing, call up the inventory screen 
and press one of the following key sequences 
(depending on how you set your controls.)

Default Controls 
L2, R2, L1, Circle, Triangle, L1, R2, L2

Control Method 2 
L2, R2, Triangle, L1, Circle, Triangle, R2, L2

Control Method 3 
L2, R2, Triangle, L1, R1, Triangle, R2, L2

Unlimited Ammo

If you win the game and reload any saved 
level you'll have all weapons, unlimited 
ammo and more enemies to defeat.