Any comments appreciated.

its very stiff and lacked easing so you could see what was going on it looks like you just repeated two frames and his head should stay in the same place just move up and down because of his running here is a running tutorial http://www.youtube.com/watch?v=8VfTolXOWI8

Thank you.

No one can cnc something this short. like, at least give us 20+ frame to work with man.

The run was a bit choppy. Make it flow. I recommend Zed's flow and easing tut.