Pretty fun, albeit also pretty buggy, if you try to shoot at someone and a tree branch or something is in the way you'll aim for whatever was in front of the guy, makes it really hard to fight indoors especially.
I liked that you can take peoples hats even though I never found a reason why =P
edit: Oh yeah and whenever you start a new game it takes a few shots before the mouse aim activates. Before then you'll just always look in the same direction.