Unlock cheats:
     To enter the cheatcodes you pause the game, select Quit -> Replay
Level -> Bonus Game Modes, then press the code.

All weapons:
Circle, Square, Circle, X, X, Triangle, Triangle, Square. 
or
Finish the game at any percentage. 

Unlock Cairo level:
Triangle, X, Triangle, Circle, Square, Triangle, Circle, X. 
or
Finish the game with a minimum of 50%. 

Infinite ammunition:
X, Triangle, X, Square, Circle, Triangle, Square, Triangle. 
or
Finish the game with a minimum of 55%. 

Infinite lives:
Circle, Circle, Triangle, Circle, X, Square, Square, X. 
or
Finish the game with a minimum of 60%. 

Invincibility:
Triangle, X, Circle, Circle, Square, X, Triangle, Square 
or
Finish the game with a minimum of 65%. 

All cheats:
Finish the game with a minimum of 78%.