Syphon Filter 3 Hints for PlayStation
Two ways on level one kill all Shi-Hao's men (and him)in 22 or less shots or complete all other mini games.
In 2-player mode, in the Rhoemer's Stronghold level, pick Ninja Gabe as your character. to beat your opponent, when you start, on the other side of the room is your opponent.
Shoot in that direction and you can't see them at first because it is dark. also shoot out all of the lights to make it darker. your opponent will have a hard time seeing you.
Also use the knife and hang from the railing above the ramp and when your opponent wlaks under you, drop and kill.