Just awesome
This is an excellent game. The only complaint I have is that after the first couple levels, it was much too easy. Maybe add a few difficulty levels for some replay value? Also, I found that if there were several zombies in a line along the barricade, I would aim at the head of one but end up hitting the torso of the one behind it. This was annoying. Maybe make it aim at the zombie head your mouse is on top of?
Anyway, awesome. got me to waste an hour of my time :)