well its kind of cool. I certainly wasnt expecting something so... colorful. As you already said yourself, the BG and render does have some quality difference, so working with some gradiant maps to try and mask that would be beneficial. The lights look kind of random, especially the one on the right. Instead of that colored BG, perhaps something more along the lines of a vibrant city BG would be more helpful to keep with the same attitude of the renders.
HAHA. If you would like my advice, just skype me sometime. Im not the most experience GFX artist out there, but I would be more than willing to help you out. Besides, having a second opinion before you submit isnt a bad idea anyway
