me again :) Can you think of a way to enliven the far right of your image? Obviously it's in shadow, but you've got a large expanse of flat surface there that's crying out for some enrichment: if this was a physical film set, I'd be asking someone to get some light up there - even if the logic of the light was expressionistic (i.e. not absolutely in line with real world expectations). I also wonder if you might consider throwing up some greenish bounce light onto the underside of that dark tunnel interior on the left - again - just take a look at this and see what needs a bit more theatricality and pop!
Great stuff :)