Super Mario 64 2

Super Mario 64 2 was the tentative title for a Mario game in development that served as the direct sequel to Super Mario 64, intended for release in 1999. It was going to be for the Nintendo 64DD, but was canceled early in production due to lack of progress and the commercial failure of the 64DD add-on. Only one demo level was ever made but was never publicly revealed. It is also possible that Super Mario Sunshine, Super Mario Galaxy, or Super Mario Galaxy 2 could have elements salvaged from the development of Super Mario 64 2, according to Nintendo during an E3 event. Luigi was also set to appear in this game, as was a rideable Yoshi. It can be assumed that Luigi would have been playable, as Shigeru Miyamoto had planned to make Super Mario 64 2 multiplayer – in fact, the first playable demo level was multiplayer. It is also unknown what power-ups, if any, were going to appear in the game.

While it was canceled, some people believe that it is the prototype disk "Super Mario 64 (Disk Version)".

Another potential sequel would've been Super Mario 128, but the game was developed in private from 1997 to 2007 before being ultimately cancelled.