Comment by MrFoof

A similarly interesting story is regarding the NES homebrew game, Micro Mages.

The goal with Micro Mages was to get a full-featured game into the same footprint of the original, "Black Box" NES releases for the North American launch, where a fair number of games fit in 40KB of ROM or less.

Video, but it's a good summary: https://www.youtube.com/watch?v=ZWQ0591PAxM

Morphcat has done other great NES games as well, such as Space Gulls and Bobl.