The team behind EmuDeck, a project that started off to provide easy emulation on Steam Deck / SteamOS have announced their own hardware with the Bazzite Linux powered EmuDeck Machines.
Well, there are already great emulators for nearly every console on Linux, all you need to do, is create a full screen app, that is controlled by controller, where you pick your games
And the hardware, of course, but this is mostly of the shelf as well, I would say