the theme is secret but you may find out what it is about by opening this spoiler
SpoilerShow
Yes, the walls have very weak normal maps so it fits grimrock a bit better.
- Pillars
Doors
Stairs
Torches
Wall decoration
Props
improve ceiling texture (?)
- Wall (2)
Ceiling
Floor (also, grating)
Pillars (3)
Cave-in + Ceiling
tell me what you think!