It's already pretty good, but I would love to see more strategy- and less luck-based game-play, e.g. by linking high-risk to high-gain events and vice versa (e.g. locations with strong zombies and more useful items and vice versa).
PS. You loose med-kits or bullets when you encounter the super-zombie, but never food items. As long as you exchange/use the med-kits and bullets as quickly as possible after you obtain them, you are relatively safe (also see T-sense's comment below). Perhaps you should change that and make it possible to loose food as well?
@dandycool: Giving a 0-star rating because of some bug with the medals is just not cool dude ...