The body bounces very unnaturally. Even if you were going for an exaggerated style, it doesn't, in my eyes, even seem to give the semblence of movement (running/jogging/ect), but that her body simply disappears into her head for whatever reason. The legs are one of the key problem areas, since they just simply move up and down. Try using a lighter color to suggest a knee bend where it is appropriate, and I think the animation will improve greatly.
