Code Entry Screen, Infinite Ammo and Health Restore
     Enter  these codes while in a level without pausing. Enabling any
cheats removes your ability to save your progress!

Cheat code:                                       Effect:
Hold L1 & R1, then enter Square, 
Circle, Triangle, X, X                            Code Entry Screen

After entering the "Code Entry Screen" Code, 
release R1 & L1, Hold R1 & L1 down again 
and enter Circle, Circle, Triangle, Square, 
X, Triangle                                       Infinite Ammo

After entering the "Code Entry Screen" Code, 
release R1 & L1, Hold R1 & L1 down again 
and enter Triangle, Square, Square, Triangle, 
X, Circle                                         Health Restore