"As Wilcox would have said, the geometry of the place was all wrong. One could not be sure that the sea and the ground were horizontal, hence the relative position of everything else seemed phantasmally variable."

And here I was thinking HP Lovecraft was just afraid of round things in addition to octopuses, penguins, black people and Jews.

I just watched this on youtube last week, great stuff.

Not discussed: use of "5d space" phenomena used to demonstrate this. The doorways lead into impossible space, which back when I used to make levels for the old Marathon series of games was something I would exploit to both create multiple levels and buildings with windows realistically, but also exploit to have say - an infinite unbroken hallway with no intersections that's shaped like an infinity symbol.

It was also used to do fun stuff like dream sequence levels, or multiplayer arenas where similar but different looking arenas get stacked directly on top of each other and there are doors everywhere to jump between the two.