The walk cycle: looks like he pushes something out of his way with each step. The arms outward/inward swing should be reversed, I think. The legs snap. They're still for a bit. Looks strange.
The jump: Never seen anyone jump with their elbows up like that. So far as I know, the elbows are usually like, downward and the arms are like, out in front, from the arms swinging back first and then heaving the body upward. I don't see how you'd be able to get that kind of lift with an arm position like that. Okay, and the knee. I like the way it lights up like that, but then the hilight just vanishes. I think it'd be cooler if there was a transitional hilight where it faded away.
...OOOoooh, wait, now that I look closer it looks like you might have actually made the arms bend right, but it just doesn't look like it. Maybe some differentiation between the hand and the shoulder would be better. Also the way the arms snap from relaxed to jumping potion makes it hard to follow the movement.
Uhm, I guess that's it.