almost perfect.
This was a very fun game. The way you incorporated time management was well played. However, it wasn't enough for a 10 from me, and here's why:
I don't want to give any spoilers or anything, but once you get the last gun in the game, it gets too easy after that. Also, I found the chainsaw to be a rather ineffective weapon due to the fact that I have to be RIGHT NEXT TO the zombie for it to hit it. And don't even get me started on hitting the dogs with that.
It was a good game. Try to improve the length of it, and I'd take the chainsaw out.