The tool I used for it is called the Retrode2, a cartridge dumper which doubles as a 2 SNES and 2 Genesis controller hub.
With a bit of patience you can even run SNES carts on a Steam Deck https://mastodon.social/@16bitvirtual/116479936082268893
Is it cheap? Nope
Is it sensible? Absolutely not,
Was it fun? 100%
It's been a while since I had Nintendo's online service. Mostly because it provides no value to me. Gotta say, while I'm glad it's there, I would not subscribe to the service just for Mario Paint.
Username doesn't check out.