Timekiller is actually pretty cool, just different from most zombie games.
Its great, but it isnt exactly hardcore. Its good for a small trip in the car or a quick game while your standing in line, not for a 2-Hour marathon, if you know what I mean. Anyway, if you want a full review, wait for someone else to post, cause im just gonna sum up my concerns. First, the violence. I mean, if it has "Zombie" in the title, you know it wont be about peace and love, but this is one of the cleaner zombie games. All your doing is slamming the stupid things into derbis and shooting the stronger ones, and yes, there is a spray of blood, but its not splatterd everywhere, like in most other zombie games. So, my point is, don't go and download it for your 5-YO, but its pretty much OK for any other age as long as your kid can handle zombies and minimal blood.