The first things that stands out about the character is the colours. The colour choices and technique creates a very metallic look, which works really well. He seems to shine but he's still soft, the fabric of his sweater looks really touchable.
I like the way he dresses, the large sweater makes him look very friendly, and adds some 'weight' to him, and the legs that look skinny in comparison still make him look a little boyish and not too big.
His face is very friendly, which I like, because his pose adds to the friendliness. He would look more natural, I think, if his hand wasn't sticking out to the side; maybe tucked into the giant pockets of his sweater, he'd look more relaxed. He's already got a sort of slouch in his shoulders that makes him seem like a relaxed sort of person, and his eyes look very calm.
I like how his face is done, there's enough subtle shading that his features look 3d and not very anime-ish at all. He also has a sort of watery look to him, in his face and especially his hair. Overall it's a really well done design