Not bad, but the design is way too simple. I think that if you add some black and white in the shirt, red in the hair, and dark blue in the pnats it will loook alot better.
Nice concept. I don't think it's really that great or anything but I think it's a good early design that you can easily improve upon. There are obviously flaws but this seems less of a finished product than just a proof of concept sketch in its nature.
Nice lineart. Now start your coloring. I'm interested how it turns out and how good the quality will be. Btw, I can't see the bottom of his hands nor pants. -_-