Its an absolutely amazing system. Doesn’t just emulate retro consoles either, but can do old computers, like Apple II and the Commodore. Since, to the software running on it, it’s “real” hardware, games work as they did originally, for better or worse.

Some of the “cores” (configurations that mimic hardware) have the ability to apply different patches, as well as “hibernate” state, so you can get quick-resume like functionality (no need to beat all of Super Mario Bros or Metal Slug in one sitting)