Could be an decent game.
I'm really sort of surprised that this game has such a low score. It's basically just a demo, and compared to most of the shooting games that are here on Newgrounds, this one is a class act. The graphics are solid and the control works fine.
Now, if you wanted to make a full blown, quality game, there are a few things that I think you need to work on. Like has been said, you need to make reloading take a period of time. As it is, there's no real point to having a limited clip of ammo if reloading is instantaneous. Also, include a variety of enemies, both in terms of appearance and attack paterns. You also might want to consider creating a visual sign that a thug has shot you beyond just a blast sound. And, create a storyline. Give the player some reason to be compelled to get to the next level. As a stand-alone game, this Flash doesn't cut it, but as a demo of bigger, better things to come, it's pretty good.