He didn't seem to utter despise this game, yet wasn't exactly thrilled either. So, it might actually be worth buying.
Zombie games can't really have a story, because, let face it, all zombie plots are now overly clichéd. Either it's a government plot, aliens, nuclear waste/virus, or a government plot using nuclear waste/virus and aliens. The only thing left would be if mother Earth decided that our decaying dead bodies were a toxin, and spat out all our corpses in order to clean herself. Unfortunately, even there, the government would find a use for it, and it would loop right back to a government plot.
Simple fact is that zombie movies and games can't really have an original plot. If you're tired of the repetition, don't play it. If you're just looking for a mindless game (pun intended), then with the rest of the review, it should be worth the purchase.
Unless, you have something better to play that is.