I like the graphics! But the gameplay doesn't catch me, sorry.
I see some problems there:
If the player jump on the head of a zombie, he will bounced up and hurt the zombie. The jump that kill that zombie doesn't bounce the player up, even if there is another zombie under him that should bounce him up. Then there is a double jump ability that is not working all the time. It seems to have problems with the head jumping.
Sometimes I have no ammo if I start the game. Is that intensional?
The zombies just appear on the screen. That feels strange! They are zombies not ghosts.