This picture made me so... happy! The textures on the two foreground characters are stunning, I really get the sense of slightly banged-up metal from the robot, and the kid on the right just reminds me of all the childhood kid-hero characters.
The background is fantastic, there is a lot of implied detail, and even through there is a distance blur, the solid objects still look solid.
My absolute favourite part is the little happy (or hurpdurp) face looking thing on the creature-robot. This is just a brilliant image to open dA to. (: