This is really nice. Great line work, clean shading, charming style, and nice job with bringing out the character in his face and the objects around him. I really get the sense that this kid has been places and seen things.

My only criticism is that I can see some sketch lines around the flag and around the rope coming out of his pack. Nit picking? Maybe. I know, its pen. And those lines aren't coming out with an eraser that's for sure. Maybe sketching in pencil next time? I don't know. Your call. But it would just give it that clean sense of completeness without the sketch lines.

Over all I really enjoyed looking at this. You've got some nice work here.