Awful, boring, sick
The worst thing about this game isn't the fact that it is actually quite sick (endless killing of people) but the fact that is the most repetitive, boring game I have ever played on the PS2. All you do for the entire game is kill people. Story is minimal, no character development and the action is just so mind-numbingly repetitive. No matter how many ways you can kill people, the result is always the same- they end up dead.
So in conclusion, unless you are the kind of person who only liked GTA because you could kill sprites, then it might be your game. If you like a game thats....well fun, then stay away.