Pretty cool.
Kept me entertained for a few minutes.. Then I died.
I think you should either rename the grenades to shotgun blasts or add actual grenades, since that got me a bit confused. Also you should make it so the player is invulnerable for a few seconds after losing health. I lost all my health and died when a soldier spawned right under me.
Could use other ways to avoid the zombies too. Other than that it was pretty cool.