Greenio's Lost Tapes

A series of recordings have been uploaded by the YouTuber Greenio, all cataloged within a playlist called Super Mario 64 Lost Tapes. The videos contain grainy footage of Super Mario 64 phenomena.

11.05.96
The video starts with Mario in the basement of the Castle. He goes to the basement hallway, where a coloring error takes place. He subsequently enters the Star door, where the Wario Apparition occurs, and the screen goes to black. After this, four black and white pictures occur. The first is a screenshot of beta Peach's Castle. Next, a picture of the mother penguin at Cool, Cool Mountain. Then, a screenshot of a beta version of Super Mario 64 with a boo. Lastly, a picture of Bomb-omb Battlefield. After this, the game goes back to the title screen. 

03.11.97
The video starts with Mario at the Eternal Star. The screen subsequently goes to black three times and Mario then dies. An error message subsequently appears with a voice playing in the background. Finally, a beta picture of Super Mario 64 appears, where both Mario and Luigi are in Rainbow Ride. 

05.30.97
The title screen first appears, but it is graphically messed up. An error message then appears, that when translated is "every copy" with a voice playing in the background. Next, Mario is at the endless staircase, but when he tries to leave a scream occurs. He then Backward long jumps on the stairs, where the message "Turn back" keeps appearing. He subsequently dies when he reaches the top. The same error message from the start then appears. Then, he is in a fight with Bowser who has text similar to his first fight but with the addition of "It's time to wake up. Please". The screen then goes to Mario is a room with two moving blue walls that crush him. Lastly, the same error message as before is flashed on a red background. 

09.02.97
Mario enters the Castle and goes to Bomb-omb Battlefield. When he enters the painting the screen flickers. When on the Star Select screen, the description has a flickering black box over it. When he enters the level, another error message appears, this time when translated it reads wake up. The title screen then appears and suffer another graphical bug. Next, a picture of Bowser slowly fades in. Mario is then at the village in Wet-Dry world. Messages appear on the screen reading "Help, The Flood, Save us". Mario subsequently goes to the courtyard and sees the lifeless body of Luigi. An ending picture is then shown, and the end of the video, a graphical error occurs and a scream occurs. 

Theorising
The description for the 05.30.97 details an scrapped ending only located in some builds of the game, and even then is usually inaccessible. This ending appears to be a bad ending where Mario fails to Bowser. The room that appears in the video could very well be the infamous Bowser Room. It shares some similarities with the most popular depiction of the room: it features grey walls with a sort of screen on the wall. With this, the video explains that the Bowser Room was meant to be used for the unused bad ending.