Missing one key ingredient...
NAKED CHICK ZOMBIE! Cmon man! I was hoping she'd show up, I was thinking "what, no clowns?" Then bam an orange afro was charging me. Oh well... Some suggestions (other than naked chick zombie) you should make day missions a part of the game like saving people, getting food and supplies, then at night you have the shootout! Plus most of the weapons kinda sucked, I tried them once and went back to my trusty uzi. Also throw in a bad ass Romero zombie with a white beard and smoking cigarettes, maybe a Savini for good measure.
All in all good work, was very fun.