Superb animation!
Not bad for your first animation (this doesn't include practice flashes right? lol) Also, I enjoyed the dark setting when that fellow in a business suit was floating towards his inevitable death. WOuld of been cool to see a river of black, gnarled hands dragging him towards the execution sight. Though, as you make it quite obvious, flash is difficult. I wish I had a flash program. With a little tinkering, who knows, perhaps a flash is possible? Anywho, back to the review, it was great nonetheless, keep at it. Like you said, it's extremely rewarding at the end. A flood of positive and constructive reviews to ease your sore knees :P Good luck with your future projects!
~ChaosWolfGod