needs some obstacles. something to get your back against. like some burned out buildings, that you can run to put a wall between you and the zombs temporarily.
it has potential. make it online, with random pairings of players, with a reset in case you get an a#@hole for a partner. then add other missions, with coop required, like one person holds down a button while the other runs, and you will have an amazing game. also, maybe make it possible for more than two to coop. that would be epic. i like this style though, so that should make artist rendering easier. but i like it.