The guy in the foreground is just messed up, and in a bad way. His expression is weird, his arms are very useless looking, and his posture sucks.
I hate the tone and shading you used in the background, and the lighting in general, but the general artwork is impressive. Redo the guy in front and the coloring, and it will be very, very well done; as it is, B+ for an amateur.
I'm just being very critical, mind you. I'm not trying to offend/insult you.