An interesting idea, but I found the camera focusing on random people to be more frustrating than fun. What I thought it would originally be, would be the camera would move to different locations, and I'd have to aim quick to shoot the zombies. It wasn't very difficult to not shoot humans, only time that really happened is when they were blocked by like a tree.
Some particle effects would have been cool for shooting people, maybe a little blood spray.
I did really like that lights turning on intro, that was cool.