Very nice, the new blending mode for the island outline looks great IMO. I like the effect for the collapsed corner of the new room, I think with a little rubble to tie it into the rest of the room it will be top notch.

You might want to consider a larger or more extreme edge/slope on the floor-to-dirt transitions in the new room (particularly along the walls). Right now it doesn't give the impression of a 10' drop to me, more like 1 or 2 feet. That, and/or possibly making the deeper pit-portion a much darker shade, either through playing with your brightness/contrast levels or placing another layer over the dirt floor made from a semi-transparent black, possibly with varying levels of transparency.