Revelations afoot in the Iwata Asks interview for New Super Mario Bros. Wii. Toshihiko Nakago, currently the President of SRD2, reveals that Miyamoto’s dream of a multiplayer Mario was born during the development of Super Mario Bros. 3.
Ultimately hardware limitations scuppered the plan, leaving the team to step back their efforts and go with the inclusion of a multiplayer version of the original Mario Bros. instead. And once again, after attempts at multiplayer Super Mario World failed, the idea was put on the backburner for fifteen years until New Super Mario Bros. for the DS began development. Sadly, the idea was once more left out, and it seems the multiplayer Mario dream was destined never to come true.
In fact, the dream didn’t die and it's thanks to the combination of kansei and increased hardware power that eventually brought us a four-player New Super Mario Bros Wii. Whether the dream of throwing a Frisbee for a dog to catch goes back that many years, though, is a completely different story.