Well, the first thing that catches the eye is definitely the hair here, haha! I can see it on the original char, and I have to say, I think you did a lovely work with it! :D The way it kind of, curls down, on both sides of the head? I think your lineart there makes it work the best!
And then of course, the happy expression and lovely blend of brown colours! It makes for a very cute piece! :)