I can't believe I wasted 2 years without this game.
The game is not without its flaws, however. First off, it's incredibly violent. If you think getting stabbed by an axe is bad, wait untill you see your head lopped off by a chainsaw, or the skin on your face dissolved by acid. Fortunately, within an hour, you become descencitized to the violence. Also, it's very easy to die. Although this really makes you focus on strategy, it may turn off inexperienced gamers. Of course, this game is really only for experts. Expect to die at least 100 times over the game (yes, it keeps track).
Overall, you must buy this game. For $20 dollars, it's a steal.