good game!
but you could do some stuff wiht it to make it better. like different levels, and a shooting animation. but i know how hard these type of games are to make at first. also, here how to make a shooting animation:
on the first frame of your gun movieclip it should just show the gun pointing. right click on the first frame of the moviclip on the timeline and put a stop(); there. then copy ONLY THE ART and in the main scene, (outside of the movieclip, the workspace) and covert it to a symbol. right click on it, and make a shooting animation where the gun goes back a little more maybe. the go to the last keyframe of the shooting animation and put a _root.whateverguninstancenameis.gotoAndStop(1);
then copy the shooting animation and put it in the second ffraame of the gun. and make sure you ---
nice game!!!!!!!!!