Not bad... hope you make the full thing though
I found the shot aiming was without fault.. you shot the head, he died, you shot very near him, he didn't take a hit... character movement too is good, with not each and every gunman the same. (That chicken though... haha, what the f...)
Features I would like to see added:
All the gunmen hit you with each shot, and shoot you pretty much straight away. That's ok for the ones close up, but for those far away, how about they sometimes miss you??
I'm guessing if you finished it you'd make more scenes too, rather than just the one background.
Reduce filesize a bit by cutting down on the pointless never-used-again gun images at the start. 1.4Mb was ok for now, but if you finish it...
Hope this review was constructive, and don't get the idea I think I'm some kind of master, this is just my opinion from a player's PoV. Keep it up, and I hope to see the finished article :)