this game seems not very cool at first, but then it prove to be addicting and fun to play.
surely the graphic could be improved and maybe you could add more different killing machines, as well as bonus and malus. but it's not bad even as it is now.
the only thing is that you should reduce the speed of the bleeding to death, because every time you get hit, you're likely to bleed out before finding a medical pack. this thing of the bleeding is a cool detail, but as it is now it seems a bit useless.
good work though! can't wait for a new improved version! :)