It's a fun idea, and an obvious concept for the theme; zombie hordes are an obvious way to have your dudes still doing stuff after dying. The way they do health is also nice, with it being direct damage to stats rather than a critical existence failure. With the game stretching out to 10 rounds I'm not sure that it'll be easy to actually have any survivors left by the end of it, the combat can be a bit of a tarpit, but with the number of attacks out there from just zombie hordes and other players, I wonder if you'll get several games with only zombies or one side desperately trying to not get eaten by the hordes by the end of it.
-Chase