Doom can make me nauseous, especially if I'm watching instead of playing. So does https://en.wikipedia.org/wiki/Ion_Fury https://en.wikipedia.org/wiki/Ion_Fury

Doom can make me nauseous, especially if I'm watching instead of playing. So does https://en.wikipedia.org/wiki/Ion_Fury https://en.wikipedia.org/wiki/Ion_Fury (an anachronistic indie game using Duke3D's engine) Theories: Doom's 35fps framerate cap; try an "uncapped framerate" port like GZDoom. Another thing could be the pseudo-3D look up/down used in many software renderers of that vintage; the world is skewed rather than rotated, so that vertical walls remain vertical when projected onto the viewport. Modern 3D-accelerated ports don't do this. (Or you could turn lookup/down off) Neither theory explains Source nausea, unless perhaps you also played it with a low framerate.