I don't know if tilt more than 90° will be a enrichment (in the final gameplay) but I implemented it for test purposes.
The doors are created with the cubes but you're right the emissiv light was too low - changed.

The current movement is from the middle of the room to the doors.
The selected door opens but you stay in the actual room (to have a look if it's a trap):
You can now move into the new opened room or change to an other door.
Entering a room means always moving to the center - that's because of the gameplay (you will see later).

I changed the door-distance and switch the light on only if the new room is entered. I think this will make the players positions more comprehensible.

The next task will be to fill the rooms with objects, hints and traps...