Oh, and I guess the flat colouring was probably to help with hiding the clever tricks used to change the level around, but it sometimes made it a bit challenging to see where walls and entrances were :)
It's true. I have played around with that mechanic a lot. Theoretically any pattern with 4 way symmetry would work, but I think the actual issue has more to do with lighting than material, and that may be more of a challenge.
Although now that I think about it, maybe not. I actually just need to figure out how far the light travels...
Thanks for your feedback!