They definitely do. I recommend GP check out PICO-8 which has some VERY real games on it like the original Celeste (by its original creators), Cattle Crisis, POOM, Combo Pool, Into Ruins, Dank Tomb, UFO Swamp Odyssey, Porklike, and much more. Most of which you can play on Itch.io for free in your browser.

I’ve been having a blast making a “real” and very full-featured PICO-8 game to serve as a “market fit” prototype — if a PICO-8 game on Itch gets meaningful attention, I’ve “found the fun” and therefore I should make “the full version” (non-PICO-8) for Steam, etc.

Speaking of your last comment: while very impressive, I feel a bit disappointed when someone's done something amazing with a Game Boy or SNES or whatnot, but the solution involves shoving an entire computer in the cartridge. This is still very cool but your console just becomes a head unit for your GTX 4080 or whatnot.