Your lighting and coloring is pretty cool. It looks like you copied and pasted most of the heads on these sewer mutants though, and thats really a pity. Also with a blurry background, your creatures in the back should also be blurred, to bring focus to the front. The one guy to the right and smack in your face, is alright, but doesn't really feel needed.

If you're looking to improve I would focus your efforts on more geschult, relying less on technological tools, and understanding how non visual, visual paths are formed. Figure out where you want your viewer to look, and direct them there purposefully. I see some real promise from this style. Keep up the good work.