Played it a few times, I enjoyed it. Reminded me of the top-down sections of Contra III I played a lot as a kid mixed with Zombies Ate My Neighbors. I won't lie though, the game is tough. I've died from just walking down the street then getting hit by zombies that popped out of literally nowhere, getting hit by a zombie I *knew* wasn't close enough to hit me, and getting shot by droids/aliens(?) before I had a chance to react. That was just the first few times I lost, however, after the first few game overs, I started really getting a grasp on what I was doing wrong, and got pretty far into the second level before I stopped.
My only suggestions would be to make the player's hitbox just a little smaller and make the piles of dead zombie a little more distinguishable from the live zombies. It's shaping up very nicely!