hmmm...
I have only few things to complain and congratulate you.
First of all, There's no sound. You probbably think that it doesnt matter since animation matters. But No. Since you are probbably new to this I will bring up these points to you. The lack of sound made it stodgy and blunt. The lack of sound or music demoralizes the viewer of watching it. Without sound it feels wrong
Second of all the animation is tiny, and unfriendly big dialog boxes, where the letter ''i'' is bigger than the character is saying it. Dont make big screens and small stickmen fighting. If There is only 2 stickmen make the characters bigger or increase the capibility of the enviorment (probbably misspelt it). Make a arena or somthing to make it more tempting. I suggest dont make dialogs in stick movies, because all the viewers of stick movies just want to see characters beat the crap out of them.
Third of all, If you like this style of animating (which is small stickmen in big arenas, I suggest you to make a stickman clusterfuck. (where in one big arena 6 stickmen are fighting at the same time with each other)
Other than that it was very good for your first piece of flash animation. If you keep this wall of text in your mind, you will have more awesome in it.
Good luck making the next one.
I gave you a 4 because it is hard for me to make an opinion in numbers.