-snips-
You can insert light entities in interiors using Torque constructor [Like what Badspot did for lights in Bedroom and kitchen dark] correct?
If so, add orange lights beneath where the lava will be, so you could have an orange glow.
Also, not to crash the party, but i made an ideea of an ice planet map.
It could be fairly habitable, There are trees over the place [Tree houses, everyone?] there could be mountains surrounding the flat area, and a glacier, and could be a sheet of water under the surface, so you could add something like a cave or a secret there.
maybe.
There are a few misaligned textures of one or two brushes, but it works fine, really.
I need to fix it up.
EDIT: Also, sorry for talking too mucuh, but as a homage, add a crashed ruins of the Abloko 11 on the moon-type planet, featured in one of the old promos for The Planets [http://www.youtube.com/watch?v=Xef3D-K7F8I]