Cheat Codes 
     While  in-game,  hit start to pause the game, then, while holding
down  the  R1  button,  enter  one of the following codes: (directions
refer   to  the  control  pad)  If  you've  entered  it  correctly,  a
description of the cheat will appear on the bottom of the screen.

     Cheats   that   do   not  affect  the  player's  stats,  such  as
invulnerability,  will  only  remain  active  in  the  level they were
entered in.

Cheat code:                   Effect:
Left, Up, Right, Down         All skills max'ed
Up, Up, Down, Down            Extra skill points 
Up, Left, Triangle, Down      Full Ammo 
Down, Down, Up, Up            Full Health 
X, Circle, Left, Left, Right  Health Limit Increased 
Triangle, X, Square, Circle   Invulnerability for the player 
Triangle,Circle,X,Square      Invulnerability for your allies 
Down, Up, Triangle, Right     Kill all the enemies in the level 
Left,Right,Square,Circle      Player gets a big gun 
Up,Down,Left,Right,X          Player gets all German weapons 
Up,Down,Left,Right,Circle     Player gets all UK weapons 
Up,Down,Left,Right,Square     Player gets all US weapons 
Down,Down,Down,Down           Rapid fire mode