It looks a little flat. It might help if you colored the walls closest to the viewer darker and more saturated. Great start!

the perspective is very confused, but the finish is nice.  good work on that

It looks really good.. No wait it's awesome!

The only lil itty bitty complaint of mine is that there could be a little more depth, in terms of color contrast, but that's really the only 'bad' thing I can think of.

This BG came out great. The WIP thread for this really shows how much better it is than the way it started, kudos.

great work on this.  it has evolved so much from the original you had, and in a good way. keep 'er up

i think ive seen it in an early stage in the W.I.P section? it has had some changes since then... nice colours, but i see no fade to black in the tunnels on the right and left... besides that very nice