Yeah sure there are lots of zombie games, most of them where you play human. Not so many where you play zombie (but still a lot). So the concept maybe still has some novely value.. I dunno.
But even though you look green and the game says "you are the zombie", you are in fact playing the human once again. You shoot with a gun and the "humans" can only punch or slap you or whatever. It is not human behavior to gang around a single zombie! That is zombie behavior. Okay, maybe you did this to bring some humor in the game.. but it really doesn't do it for me. The game totally lost its believability.. As a zombie I want to bite humans, rip them apart or whatever, infect them so they become zombies too. And I expect humans to be smarter than go hug a zombie to death with all their friends..
Also, collisions are handled very poorly in my opinion.. but okay, you only had two days..