Syphon Filter 2

Super Agent mode:
Pause the game, highlight the "Weaponry" option, then hold L2 + Select + Circle + Square + X (simultaneously). If you entered the code correctly, you will hear a sound. Then, enter the options screen and choose the "Cheats" selection.

Super Agent mode:
Pause the game, highlight the Weaponry option, then hold Select + L2 + Circle + Square + X. Enter the options screen and select Cheats.

Movie Theatre:
Pause the game, highlight the Briefing option, then hold Right + L1 + R2 + Circle + X. Enter the options screen and select Cheats

Infinite Ammo:
To get infinite ammo for all of your guns, pause the game and go to the map screen and press X(2), O(2) and Square.

End Level:
Pause the game and highlight the map option then press and hold: L2 + R2 + Right + X + Circle + and Square. Then just go to options and go to cheats.

Hard mode:
At the title screen, highlight the One Player option and press Square + Circle + L1 + R2 + Select + Up + X.