It would seem that poking a screen would be boring and easy, but its not.
In itself, the storyline is pretty dumb, but hey, its just an excuse to bust caps in zombie ass. There are zombies, mostly variations of a skinny or fat zombie, with different appearence and increasingly higher health and ferocity. You start out as Robert Steiner, jailed for life for a crime he didn't commit, and one day, a security breakdown occurs, and everyone is zombies. Each stage is up to 5 minutes long, and there are 3-4 stages in a chapter. The replayabilty on this game is great though, so don't mind the shortness. I find it fun to go back and keep getting better stats (i.e. never getting hit, perfect accuracy, etc)
For a game made by Dream-On Studios (wtf is that?), a random company, this game is really surprising its its fun. The graphics are meh, but they suit the zombies well and blood squirts everywhere. Body parts also sever quite nicely. Each place is distictly different however, and they are'nt that bad.
In conclusion, i fully recommend getting this game for a fun game that you can pick and play, even after you've beaten it.