Here's the truth
The zombies are the true heroes of the story, providing both comedic relief and stress relief. While the story is interesting to follow, you will often find yourself on random killing sprees or hunting for a better weapon. Or battling the save system. This save system isn't horrible, but it is a tad bit annoying when you die and find out that you haven't saved for the past five real world hours.
This game truly stumbles during the ridicuously tough boss fights. You will often times resort to cheapness to win, and if this happens, something has gone wrong. And, the true ending nets you a cutscene that leaves you craving an explination as to why you just beat this game.