tonight's rabbit-hole was “can I get Amiga demoscene floppies running on my RetroArch PC,” and so
I also remembered that I have a bunch of Virtual Boy games and a pair of anaglyph glasses meant for the TEC Redshift, which took us down a very dark path.
There's a Virtual Boy emulator for VR headsets, but it's years out-of-date and the focal-distance of the virtual screen is about three inches from my nose, so wearing paper 3D glasses with red and blue plastic lenses is the better experience, I think.