Vision - 4 Stars - It is a good idea, and the idea for the pose is perfect.
Originality - 3 Stars - It's not uncommon to see a boy wit ha guitar, even though you portrayed better than most people would.
Technique - 4 & A Half Stars - Very well drawn and the coloring and shading skills are wonderful!
Impact - 3 Stars - It's a nice image, but a boy sitting on a desk with a guitat isn't exactly life-changing. ^_^;


Okay, so, you asked for a critique. Here it is. =3

The only things I find that look a bit odd are the guitar, the way his foot is placed on the drawer, and how the book's page is flipped. The hands also look a bit odd, but they are still much better than I could ever do! XD His neck looks a tad thin when compared to the rest of his body, as well. I would say, with the foot, try making it a little more turned up. I think that the heel might be what's making the foot look a bit off. As far as the guitar, the only thing I see there is that, with how it's turned, that either the main part's angle being turned inward toward the boy slightly, or that the angle of the handle-thing(the name escapes me, at the moment) be a little more outward.

I hope this helps!