Nintendo's recent “celebration” of recent anniversaries for the Mario and Zelda franchises. Releasing on November 13th, 2020 and November 12th, 2021, the two “revival” Game and Watches are capable of doing a few things, despite their unsurprisingly lightweight status. Containing an ARM Cortex M7 core, 128 KB + 8 MB of flash memory, 1.4 MB of RAM, and an unknown screen, these little systems can emulate a few eras of game consoles with a simple set of hacks.

https://gamingph.com/2020/11/nintendo-game-watch-specs-and-tear-down/

Whether these emulators support operating systems for these consoles is unknown; it must be looked into further. Consoles without meaningful OSes are not included.

https://github.com/kbeckmann/game-and-watch-retro-go

https://www.reddit.com/r/GameAndWatchMods/wiki/homebrew

Coleco ColecoVision – retro-go

Nintendo Entertainment System – retro-go

Nintendo Game Boy (Color) – retro-go

Sega Master System – retro-go

For general information, see the Game Console Revisions Overview.

There are two versions of this console, arranged chronologically.

Comes with 3 games: SMB1, SMB Lost Levels, and the reskin of “Ball”. Technical specifications are identical to the Zelda G&W, as for potential mods.

Comes with 4 games: TLoZ, Zelda II, Link's Awakening, and the reskin of “Vermin”. Technical specifications are identical to the Mario G&W, as for potential mods.

https://www.reddit.com/r/GameAndWatchMods/wiki/faq

https://en.wikipedia.org/wiki/Game_%26_Watch:_Super_Mario_Bros.