looks nice overall, just the abs to sharp, not sure if thats what you wanting, also his pants I think you would get a better result if it were a separate object, they seem a bit square-ish,
one more thing I noticed the topology in your does not seem to flow
here is a model I did after Kurts ninja tut, it's not perfect but it put me in the right direction, if you want I can post more wires to help

https://www.mvorster.co.uk/SimplyChallenges/frame.jpg
Dae