Needs Action Script
The lack of a preeloader and having to stare at a black screen for a while detracts from the whole experience. You're logo and the black screen fallowing it took so long that I nearly closed the window, beleivng that the short was over.
As far as the artwork goes, there would be a tremendous quality improvement in the flash if a little more movement was added. The still character clashed with the inflating bag as the flies (which were obviously animated in groups) were sucked in.
I understand that aminimaing is very tedious and time-consuming, but eventually you will become faster at it.
I will not carp about the weird boarders because I beleive that they are an artifact from porting from ToonBoom (which I have heard is difficult to do).
I do however like the colors and the somewhat abstract characters. With more practise your work will eventually shine.