ugh, rapidshare, filefront and mediafire. Dropbox exists, might as well start using it.
Use that link and you'll get an extra 250 gigs (a total of 2.25 gigs) and no upload limit, plus you don't have to log in to anything to use it.
As far as the game itself is concerned, of course it could use some work (I'm sure you already know that) but I definitely think you should do those suggestions that Bartosh mentioned.
On top of that, a few quick ideas you should be able to figure out easily
1) reset the point on the gun so the bullets don't fire from his head. Just choose the image point in the image editor and make sure the bullet spawns from that image point, not just the center of the character.
2) create a spawn point for the zombies. put some cracks in the wall and have them waddle out from there. It could be something simple, like create a sprite that is just a flatshaded box outside the play area. Create a variable for a timer, call it timer or something. When that timer reaches 0, then create a zombie and set the timer to some number + a random number, such as 50+Random(100). When that timer number is greater than 0, subtract 1 from it to make sure it counts down (but does not go passed zero). If you want to make things really interesting, when the timer resets, set the value to "ValueA+Random(ValueB)". Add a condition to the spawn event to say if Value A is greater than a certain number (whatever you want, this is just to prevent the spawn points from spawning instantly), then copy the event and change the greater than to lower or equal to. On the greater than event, subtract a certain number from valueA and valueB, then just initialize them both to whatever you like, this way as time goes on, the zombies start spawning much quicker.
3) Make some scenery, maybe some walls, whatever. You can also make some crates or other objects and give them the "physics" behavior so they can be pushed around, just make sure that you give the physics behavior to the character and zombies as well.
4) Don't make the zombies so fast. I'd settle for slower tougher zombies any day.