Not bad in having the zombie getting blown to pieces. It'd be great to have health and ammo pickups in the levels. The problem I am having is that sometimes the zombies get killed by my bullets sometimes it doesn't. I don't know if that's a glitch.
Thanks for playing! I agree, my collision is bad- I didn't notice it when building until it was too late :( I think I was spawning to bullets too far away from the player and they would end up not registering.