Syphon Filter 3 Cheats
Defeat the game to unlock the "End Level" cheat. This will allow you to end the level in missions and mini-games.
Jungle Level in Multi-Player Mode
In the Jungle level, rescue the two women. This will make it available in the multi-player mode.
Unlock Super Agent Mode
Suscessfully beat it once. Once starting a new game, pause it and go to the options menu. Turn "Super Agent Mode" on to activate one-hit kills.