CONS: He's so tall yet his legs never get to be straight, his torso has that cross drawn on it that should deform a little bit more considering his shoulder/arm. His arms look like they're mechanically going back and forward. You could let the hand where it is one or two frames longer rather than going along with the movement all at once, it's a little thing but it would give a different feeling.
PROS: I like the head bouncing and the fact that you remembered to make the whole body go up and down. By the way, wouldn't that axe be more heavy thus pointing to the ground rather than to the sky when he's not using it to attack? I also like the idea of a thin skeleton with tiny feet, a complete version could be really cool.
(if this character had been beaten up quite heavily the fact that he can't get his legs straight would be quite expressive! as if he's really suffering, so the leg thing isn't necessarely bad, depends on the character you want to express 🙂 )