Okayy...
I have to be brutal I'm afraid. I give honest reviews. You can read my user page.
While this is clearly a well below average flash, there certainly is a glimmer of light somewhere. There were some little bits that were slightly funny and it is indeed possible that it could end up being quite a stress reliever. But that's about it.
The graphics were poorly done. In some frames it was like you barely tried with the blotchy 'blood' stains. And a few of the images were clearly taken from somewhere else.
There are a whole host of steps forward for you.
1. Improve interaction with the images - There were a couple that allowed me to shoot in different places and get a different end result. It reminded me of an old Kill Barney flash that had you shoot it certain places and the effects would happen on those places. Have more variety in the interaction zone. Quite frankly, this is close to just clicking a 'next' button over and over again. It's hardly a game at all.
2. Clean up certain images. Improve your drawing skills. Or at least make it look like you tried. You clearly didn't in some and just used some random smudge with Paint.
3. Animate. Simple and easy. Doesn't have to be complex. Animate something. Anything. Still images of 'before' and 'after' shooting get boring real fast. And you had like 20 of them in here. Animate some of them. First time for everything, so why not take a stab at animating some of this.
4. Include sound effects. It says sounds taken from somewhere, but I played the thing and there's no sound at all. Sound improves everything. I particularly think a shot at homer and him going 'doh' and dying would actually have a much better outlook than a silent nothing.
5. This is a platform for actually making some humor. Use it. Don't just leave it at 'killing for no reason'. Then there's obviously 'no reason' to be playing this thing. Think up some gags and put them in.
Alot of work to be done. But one can only go forwards from here. I wish you the best.