Well, it's a chibi so there's not really anything wrong with it. Chibis can get away with a lot of exaggerated anatomy. Or no anatomy at all.
But this is my opinion:

He just needs a bit of feet? I guess. I'm really bad with perspective, but his legs seemed kind of flat, so I just tried to make them look grounded (I guess that's the term?) And I thought the arms were too short, but that's just an opinion. It's pretty well done imo. I wouldn't worry about them. These are just my opinion.