Good.
A definite break from all the flawed zombie-shooting madness games, this game teases the brain, it actually makes you think before you click.
The graphics are pretty nice, the gameplay is really good, it's this game's definitive feature.
A suggestion I would have is that you might have wanted to let us shoot the zombies in any body part rather than just in the head. It makes it simpler to get higher scores, so that's why I suggest it.
Anyhow, the medals could've been a tad more significant, that's a con.