You guys are nuts- I don't even like these kind of games and this had me hooked. There are some easy ones, some hard ones, and some kickass ones. The music is creepy more then it is calming, but with an option to turn it off, that's no problem. Kept thinking it was gonna be Cloverfield all over again (which, by the way, is a horrible movie) but stunned me with the sunrise and the way the whole picture changed. The hand telling you how many you have left- then going to the peace sign when you win- is a nice touch.
Found a cheat! When reloading, click 'Menu' in the lower left corner. You'll keep reloading, but the zombies will stop moving! Also, the Options button won't work.