Remember the name...

Nice work! Let's start with composition. This is very straightforward composition, like a magazine shot or a character bio piece. It's a good choice, and makes this look professional! I like the areas of white around the figure, which contrast with his value. The spackles are really cool.

The vignette is a good touch, but I think there's a slight bit of too much empty space down at the bottom, and not enough to the right of the words.
The size of the words balance his figure very well, but they are starting at the top of his head, and I think they would be better balanced centered horizontally with his figure.

His face is excellent, but his body anatomy is lacking from the shoulders down. He looks a little bit like a gumby person, especially in his legs. His legs seem too short, or this is an attempt at foreshortening that doesn't read properly.

The shading is really nicely rendered, but a little too smooth in places. I think this super smooth shading is making him even more gumby-ish, because he looks very round and soft. Consider some harder edged shadows that create the illusion of volume.

Nice choice on colors! The hues are all really cool - it might be fun to play up the warmth of his yellow outfit more.

Last but not least, the words are a little hard to read. Consider making a drop shadow closer so that they pop more.