Neat game. There's a pretty serious glitch though. I'm not sure what triggered it, but I reached a point where I couldn't shoot. I think it might have been the number of ammunition magazines that I was carrying, but suddenly it wouldn't shoot.
Also, you can't die, but that seems like fair compensation for the gun suddenly breaking. Also, managed to kill quite a few zombies in melee before being dropped down to one heart...and quite a few after. I was still trying to get that gun to work.
Reloading takes a little getting used to. You might want to consider adding a fill gauge to show how long to hold the R button for.