Man, you've really got some potential, especially with the hard perspective you tried to pull of here. The line art is kind of sloppy compared to the other pieces you did. Also you should pay attention to the lighting. Assuming the room he's in doesn't have any lighting (lamps, light bulbs and such) you might have wanted to make the walls behind the character darker and put some more shadows on the left side of his body. But it's a really good piece overall, and I really love the peaceful feel it gives to me.