Questions about one particular type of zombie?
Your coding is well-constructed, and your music is good. Some advice on how to improve one's score against your particular zombies would be better.
This is diverting but not useful; what type of zombie is "in" changes from decade to decade, and how best to survive them changes with it. I realize you're going for the current fashion, but that will change within a few years -- just like powerful but fast-decaying alien-made zombies, once all the rage, are now out.
I'm surprised at how low you rate certain weapons, particularly those with long reach and good stopping power. And hand-to-hand martial arts against something constantly leaking infectious fluids? You must be kidding when you rate that as useful!