This is better, but if you want him to look older, like, in his 20's, you need much more defined shading around the face, and make the eyes more... human-like. But I don't know what sort of age you were going for. Maybe try something like this:

Hey, what do you know. He looks like a person. This is super-quick, but I think you get the idea. Much more defined, making him look older because he's less round. Experiment!
EDIT: I forgot to do this, but make sure to add some highlights to his hair, and extend the shadows on the hair. Also, I was pushed for time so I didn't touch his eyes. Look at
http://www.youtube.com/watch?v=GAi7cHiaf-U <That.
Good luck, I love this piece so far.
Toodles!
Shrike