User blog:The Plant Developer/Super Mario 64 2 is B3313 confirmed: The Storyline

After the events of Super Mario 64, Mario receives a totally real cake from Princess Peach! While he is enjoying some cake, Mario didn't realize that he had a high fever, and then fell asleep! Thus he began to dream about the Shoshinkai demo of Super Mario 64, albeit very off such as the back of the castle being expanded, and lacking some moves seen in the demo. It all goes well until he beats Bowser in the Dark World, in which it turns out it drops a red star instead of a yellow one... And after collecting it, Mario had noticed that something's gone wrong! Other areas are accessible now, the Personalization A.I. has awoken and the game has opened up to Mario very properly. Will he defeat the Personalization, erm, I mean Bowser that is overpowered in the Eternal Fort once and for all, or will the A.I. defeat Mario? The adventure begins once again with over 300+ areas, 400+ stars and 13 red stars, waiting for Mario to collect them all ...

This confirms that B3313 is indeed the sequel to Super Mario 64, and as such it's now titled as, aka -- Super Mario 64 2: Internal Castle Plexus.

And if the text is underlined, then this is exclusive to B3313 1.0. Otherwise, it's B3313 0.7/0.8's plot.