I was thinking this would be the old trope of implementing a single-pixel X windows server.
Why stop there? I’ve implemented a 0-bit display driver that runs on any device, at any resolution, and frame-rate with no overhead or RAM usage!
As I recall, Doom ran very well on a 66 MHz 486DX. It ran on a 16MHz 386, but with less than one frame per second. A modern M-profile Arm core is more powerful than that. Fitting it in 108kB of RAM was the surprising thing - Doom had 4 MiB as a minimum requirement and 8 MiB recommended. I’ve no idea how they made it so much smaller - I’m guessing by having some word-addressable flash that was used for all of the static data? The GitHub link and the announcement link are both broken.