I think the design looks great! The animation came out a little quirky, and the motion doesn't look as natural as it could. If this is an idle animation, there's too much emphasis on the blinking (his whole body looks like its lurching with every blink) and the right arm skips up right when he blinks (the one with the sword).
I think the overall motion is good, but its too exaggerated for what you were going for. I would take away all the overshoot on that blinking frame in his face, and make the arms move significantly less. There is also something quirky happening with the right knee and right heel, which shouldn't really move at all.
I think making every motion smaller would greatly improve this animation. The hair moves wonderfully with the motion of the head, and I appreciate the folds changing in his clothes when his abdomen crunches. The turning of his head and his hand are super great subtle animations that add great volume to the character. And again, the design and color are really stellar. The pieces are all there, if you just make the motion more subtle and small, I think this would be an awesome idle animation.