Super Mario 64 2

Super Mario 64 2 is a cancelled Mario game that was going to be the sequel to Super Mario 64. It was going to be for the unpopular Nintendo 64DD, but was canceled early in production due to lack of progress and failure of the 64DD. Only one demo level was ever made. It is possible that some concepts of this game are included in Super Mario 64 DS. It is also possible that Super Mario Sunshine or Super Mario Galaxy could have elements from Super Mario 64 2, as Nintendo said in a past E3. If Nintendo would have had more progress on the game, they may have released it on a cartridge.

Luigi was also set to appear in this game, but it was unknown what type of role he would have played; however, it can be assumed that he 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. Miyamoto also had stated (while still in the process of making the game) that he was thinking of releasing the game on an entirely new gaming system.

WHAT THE HECK IS WRONG WITH NINTENDO?!
we sadly don't know.