ok maj
As for you frexx, I think you should add some more pipes other deformities into the hallways (as previously brought up also) and throw in a few varying texture for the ground, ceilings, or walls in the hallways as you walk down. To me, it seems like the main room has all the work put into it right now and the corridors seem a little neglected. Most likely though you are probably still getting to them.
Also, why did you remove the grated bottom in the main room? I thought with a little bit of tweaking it was going to be hot to have multiple levels to play on.
Keep up the good work.