As a turret defence game it's pretty solid, but there were a couple of things that irked me. The target choice of the turrets often left me despairing. I lost count of the number of times I shouted at the screen when a turret ignored an almost destroyed zombie that was about to slip past my lines in favour of some less important target. And the zombies with machine pistols seemed to outrange my gunner squads, and enjoyed holding back to snipe.
Overall the theme didn't really match the optimum strategies. Spamming infantry isn't the way its done in fiction!