I like your design, pretty cool. The issue I am seeing is that your pose is very stiff and lacks gesture. Also, your spending too much effort on the anatomy and not on the overall shape of the limbs. I did a quick sketch to show you what I mean.

Make sure you give your shapes volume and perspective so that they don't look flat. I did a quick sketch to show you what I mean.

Great!! I liked too much your gestures, but maybe they can be better... more dynamic. I loved last one :)