hmmm...
first thing when submitting a stick flash - make sure it's great.
I mean, people see sticks and they go "oh. Sticks."
From here on out, you're in for a tough ride with the audience.
I suppose the following tips may help:
-this one works in general - make sure your background is on a background layer, and, if you're using sticks, you might just want to make a simple, but nice looking background. This whole paint-brush tool thing you're doing... well, it doesn't work for ME at any rate. I would prefer lines with a few light gradients towards the edges for highlights, anyday.
-make sure the animation is fluent, or at least well done. People don't mind less frames if the actual drawing or stances make sense. This is especially important for stick animations, as people will be thinking "come on, you could have drawn more frames for that, jeez, they were JUST stick figures!"
This is one that I would highly recommend in the case of using many characters on one screen.
-make your world a living, breathing thing. Don't have static characters that do nothing, and I mean NOTHING, until the stick character comes and attacks them. Have them smoking a cigarette, or just talking lightly with another stick figure (miming, of course... you don't want to take the attention away from the main stick character)
It makes the animation as a whole look a lot more interesting.
For a first animation, as a test of your current abilities, I can say "well, you've got basic animation down."
Do you know how to tween? Or Motion tween? Or how to use movieclips or graphic symbols? If not, I'd suggest looking up on them (well, when you're ready to move on from stick figures, anyway)
Good luck with that.
I'll give this a 5/10, 2/5... passable (compared to many other things on this site...) but not very great. I do, however, look forward to seeing what you might do in the future.