Pretty fun, the art style is great and the game is very intense. Good job!
Two things I thought: the fast guys are very fast, so at some points I felt that all I was doing was trying to kill the fast guys. However, I think forcing players to make decisions and cut losses is an exciting mechanic to have.
Second thing: I felt there was not much audio feedback. I was really hoping to hear gunfire noises, so I was a bit disappointed there were none, and no noises from the zombies either.
Other great job!