Woah! Thanks for sharing, that video is amazing, I'd love to see an actual game using that effect.
Also look at myhouse.wad for actual Doom in actual non-Euclidean spaces.
The only game to give me motion sickness by watching a streamer playing it, and no motion sickness at all playing the VR version. Very odd.
(not exactly the effect in the video you responded to, but similar category)
I suppose something around non-Euclidean levels without user-created portals could be interesting, but I think it'd be hard to flesh that out to a point where there's enough there for a whole game without coming up with some other gimmick.
> They are also used twice in the campaign (contrary to the commentary's claim that they are only used once): in the GLaDOS wakeup sequence where they are used to connect the incinerator shaft to GLaDOS' chamber, and in Finale 2 where they are used to connect the "trap" chamber to the main map. These are the only uses of this entity in the final game.