I'll keep in mind with the shades, and yeah, it's a series of horizontal mineshafts. Thing in the upper right is an elevator, and the diamond shapes are lights embedded into the walls of the elevator shaft.

And yeah, I could probably stand to smooth out the lights a bit. If this get's rejected, I've got a good starting place, I suppose. :p

 

Yeah, the size is a definite issue that I'll be more careful with later on, and as for fewer shades, I hadn't actually noticed that, but I may have went a bit overboard with the amount of white in it.

Yeah, that's where I originally found the style, although I was referring more to the shading. Looking at it now, it seems more like a simple gradient rather then a specific style.

I'll prolly keep the question in the description just in case, but if you happen to know who the user in the minecraft forums with that avatar is, that'd be nice to know.