I still haven't really gotten the hang of AAed sub-pixel movement, I just wiggle around the pixels inside the outline to give the impression of more movement.
What I think would improve this is if the movements are circular and opposing each other. That is, if you have the entire body rotating clockwise, make the arms move counter-clockwise. Loosen up those shoulders too, you can have one frame with them up, and one frame with them down to really push the breathing and keep him from looking too robotic.
I like to examine each body part individually as I go, and make sure they're all moving in smooth curves. If you look at the close arm, it's kind of jerking back and forth, juggle the lighter blue and the flesh colored pixels around of the end of the arm to get a smoother motion.
If you look really closely at my animation, you'll also notice that even the chest changes, just by a few pixels, but it breaks everything up even more and makes it seem more alive.
One thing I didn't do that would probably look good would be to make his meat pounder (^_^) rotate around somewhat during the cycle, if you make it lag a frame behind everything else (going up and down) it should look heavier as well.
Keep those feet planted, I notice that the front foot is wiggling back and forth, it makes his stance look a bit weak.
Do the same frame lag thing with the cape; when the body moves up, the cape stays down until the next frame, when the body moves down, it stays up till the next frame. This'll make it look lighter and "floatier."
