Oh come on.. I'm not a pixel artist and even I can notice that there's a pretty obvious problem with establishing a light source (or more so, alternate light sources) in the piece that just really downgrades it. As a whole it's nice, but if you can't see a problem, especially on the box arrows, you need your monitor gamma raised or something.
I just noticed the box arrows. Thats pretty bad since it is flat...but everything else is fine.