I love the mood you've set here.Though it seems the shaded left leg needs to be higher on the floor than the right one.It almost looks like his legs are crossed like he's doing Riverdance.Realy like everything else including the subtle HUD.No complaints on the brain.I like the fact that it doesn't look human.
Somehow the pic could use a wall of skulls but maybe I've played too much Darkseed. Interior decorators are always wiped out in the future ...
Anyway its a cool pic. Look up a reference for the brain. The brain tank holder has great design, but maybe could use some cleaning up.
I really like the far background and the interface. The foreground, on the other hand, has a number of issues. The darkness on the floor is real sloppy, not at all the skillful look of the back. On the subject matters, I would do away with the black outlines, it makes it look flat against the depth of the picture. It might seem like it'll blend in a bit with the background, but some smart alternate-lighting highlight could really help that. The brain's lineart is not at all good(sorry if sounds offensive, but I would recommend just redoing it and it's wires entirely). On the brain's machine, darken it all a little bit, with the highlights on only the most extreme edges.
May I add though that aside from the all black on back leg, your use of the light source on it is expert.
All in all, you're pretty good at this. You just need a little bit of refinement. Good luck in the challenge, I just may vote for you.
Very nice background. My only crit would be to have the objects such as the computer and the incubator, to also have a bit of shadow casted like you've done with the guy, to make them feel a little less floaty, along with a little more detail inside the incubator.
Thanks for the coments.
When I started working on pic I had totaly different concept in mind, but final idea came along the way. Trouble is that by then I lost every sense of light source and perspective. I wanted to make it in time for challenge, so I rushed it too (specialy floor which I did last). But now I have time I will try to improve it. Already redid brain, and working on floor too. Will update it soon.