Super Mario 64 2 (Cancelled 64DD Game)

Other than that it was set to be released in 1999 for the 64DD, we know Miyamoto wanted Luigi to be in it and make it multiplayer.
I really wish it was one of those planned 64DD games that made it to the regular N64.
Even if it wasn't multiplayer, it would have been really enjoyable.
According to Miyamoto, elements from the game were passed on to Super Mario Sunshine, Super Mario 64 DS, Super Mario Galaxy, and Galaxy 2.

I loved Super Mario 64, it's still my favorite game of all time. If it would've been a good game, I would've loved if they had released it. But I mean, I can see why it was cancelled. They had ideas for GameCube. In the end it's probably better off being cancelled, but it certainly would've been interesting to know more about it at least.

Still, I wish they would make more of a sequel to the original. I haven't fully enjoyed a new 3D Mario since the original Galaxy. I mean, Galaxy 2 and 3D World were good, don't get me wrong, but I haven't gotten the same amount of enjoyment from them that I did the others.