you have your style, and it looks nice. the only thing i would advice you about this drawing is to check out for the ligth source, since there are some sligthly shiny spots in the clothing and they all seem to come from diferent points. also, if the left hand? is a weapon, and it is metal, you may consider adding some shiny...er... ligths to it, to give it the metalic feeling.

the background is realy nice ( me likes it ) but the white part gets a bit cofusing whit your signature, you can either change it to the other side (left) or change its color, maybe a grey , a ligth gray, to make it clear.
good luck.