I've been reading "The Hobbit" again for the dozenth time. That's melting a little into the character, since Mario is taking on a slight Bilbo appearance. I'm embracing since I feel like young Mario is also somewhat innocent and aloof.
Also something worth of note is the eyes. That's the very first bit of detailing I do to characters, especially with children models. It sets the entire tone of the character. I always recommend working that out from the start.