First I must say this game gets fun but also difficult very fast :).
Loved the gameplay. It was smooth, and the bullets honestly never miss, all taps are registered, it was a smooth job.
The presentation were alright, when I read the hook, I was expecting to play a zombie, but I found myself standing guard and firing at incoming tanks, so was a little taken aback with that.
Yeah, I mean, you're pretty much tapping maliciously on your screen to slay people, that's pretty diabolical
Overall, felt the creativity was lacking a bit, and the presentation could be better, but fun, simple and not surprisingly short game because of the difficulty.