There's also backface culling (the cylinder around the central cube is marked as double-sided, hence no culling there) but there is still no clipping or occlusion.
@philipptr: I'm guessing your technique is to calculate the angle of the point, add an offset to it, then convert back into a new coordinate? I just adapted some 3D point rotation code I had, simplifying (mathematically) it and removing any references to z.
I will probably not use textured walls - not so much for performance issues, but for aesthetic reasons. Scaling a texture down on a wall displayed on a 96x64 monochrome display (without antialiasing) looks pretty ugly. Simple lines look a lot cleaner.
Oh, and hello aCiD2 [wink]