Okay wow dang, so many other people got to this and said a lot that I was going to say. But, I will definitely back them up and say that the hand is a bit too skinny for how wide his face is here. Men's hands are usually wider than what's depicted here. Also, the angle of the shoulder is a little awkward. It looks like he's turning his shoulder towards the viewer but then it also looks like he's pulling that arm back. And backing up what *whitetrashpalace said, adding some flew to those fingers will give it some life!
I also think that toning down the hair will help bring the focus back onto his face. Even if it's to just knock back the outer edges so the brighter bits are closer in to his face (for framing :"D) Something that may help with this is using some colored lines instead of the dark outlines you have going on here. That will soften up the areas you want to draw focus away from and drive a deeper impact on the parts that are darker. Personally, I am also not too huge of a fan of the thick eyelashes on the right eye (his left) They're a little distracting in their lushness, though the other eye doesn't bother me as much.
Last little nitpicks: watch out for how shadowed you make that area next to his left eye. It looks very deep, which is extremely contrasted by how much his eye sticks out. Also, his left eyelid isn't quite matching up with the curve of his eye. Eyelids usually connect right down into the little tearduct in the corner of the eye.
Anyway, crit aside-- the colors on this are SUPER nice. I really love your palette and the not-quite-completely-smooth shading you have going on. SLICK.