1 - The graphics are... small and in my opinion not that great apart from the HUD, but I have nothing against that, because graphics don't necessarily make a game.
I helped a friend of mine make a game called Time Loss, which is still in development but going far, the graphics are just a tiny bit bigger. So this is fine.
However, for this type of game, with small graphics, the other elements have to be quite good for it to work, IE: Story, GamePlay, Mechanics, Features.
2 - To make a point but trying not to seem harsh :S...
I myself am making ANOTHER top down zombie shooter, and I find it funny that a game with this much work, in comparison to mine, has gotten more popularity...
It actually quite annoys me, but I'll let it be and just work more on mine and try to prove them wrong.
(I can see if you made Death Worm, then projects like yours would get a fair bit of popularity.)
3 - The story... it's a typical starting point or mid point, but nonetheless a good one, especially for a demo.
However no story features come into play when you are actually playing the game, except for the current objective/s... but I guess that's to keep a nice and simple
way of dealing with the goals in the game.
4 - The gameplay - I rather do quite enjoy!
It's hard enough to make you think twice, or even perhaps a third time, but not so hard you'll quit and not come back.
I like the "I'm out of ammo and I can't kill them all" feeling I get, because in reality, it would be a lot like that, and you wish you had more ammo.
5 - The AI, I honestly don't see why people are bragging here... but there is definately some effort, so nice job, it's got a semi-realistic zombie feel to it for sure.
I do like this, but I'd like to see a little more, especially if the other features, like the graphics, don't get upsized in res and detail later.
A decent start, as the title suggests, it would be better story driven than graphics and action gameplay.
I reckon it makes a fun small and simple game to play.
I prefer this a lot to Zombies, by Jimmynator, simply for the fact that guy has no originality or anything artistically nice in his game.
(I couldn't play his game for 5 minutes without being completely turned off)
Yours, however still in Alpha/WIP... has surpassed quite a few GM games. You show a nice starting effort.
If you want to see my Zombie Shooter: DeadBase WIP (currently Alpha)
or if you'd like to Email or talk to me on MSN: firstname.lastname@example.org
Maybe Skype?: jwrac-productions
Thanks for reading!