Could do better
The sounds were, for one, too loud, and the artwork was below bad; the instructions were not added and the only way you could play was by guessing that you had to click to shoot a bullet. That could be forgiven though; there was a "bug" that I found, which may not be a bug per se, but if you click any body part apart from the head, then the head will automatically be decapitated, even though you didn't "shoot" the head. Now, I don't know whether it was intentional or not, but that's generally not good. There was no music after a while; while I was writing this review the music abruptly stopped.
~~ Good points ~~
» Somewhat okay music
» Not totally horrible
~~ Neutral points ~~
» Music stops after a while (i.e. it doesn't loop)
~~ Bad points ~~
» Bad artwork (Stickmen? Really?)
» Bullet sound was too loud
» No instructions
Not bad for a first attempt, but since I don't think it is your first attempt, a 1/5, 2/10 from me.