A damn good game.
I won't tell you what's great about the game, because everything is good. My only complaint? Not enough stuff! Once you find all the weapons and fill up the camp with survivors, there's nothing left to do but shoot up a crapload of zombies. That part is fun, don't get me wrong, but the best part is earning and collecting new stuff and upgrading your camp! My suggestion would be, if you make a sequel (which you should, because this one is great), add more weapons, a bigger survivor capacity and maybe some extra upgrades for your camp (extra metal plating, gun turret, spikes, whatever).