Heres some tips
You need to: Work on your graphics. Use Krinkels' graphics if he lets you.
Animation: I'm not sure, but I'm guessing that was only running at about 12 or so frames per seconds. It pays to make alot of very small frame by frame movements and let it run at 40 or so fps, it'll look so much smoother and better.
Make some better backgrounds. Just add a building or a tree and make sure the lines are straight and accurate.
Well, hopes that helps. Keep going!
~Mulletman