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. The voice is in Japanese but the voice roughly translated says "The area reached in the game was not supposed to be accessed by the general public. Turn off the game system and send us a copy of the game for confirmation. Don't ask anything else. Luigi is not part of this game. He does not exist in this title. Talking about this event to anyone you know may have legal consequences. Thank you for understanding." 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 in a room with two moving blue walls that crush him. The same error message as before is flashed on a red background. Lastly, the screen cuts to an image showing Mario flying with the Wing Cap towards an unknown location. 

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, with a creepy variant of the Yoshi’s Island map music from Super Mario World playing, and the end of the video, a graphical error and a scary scream occur subsequently. 

12.20.95
This seems to be a commercial accidentally airing on Cartoon Network back when the Nintendo 64 was called the Nintendo Ultra 64. It starts off with regular beta Mario 64 footage, but then, at 0:38, the infamous Wario Apparition occurs. The commercial then switches to a screen saying "EBS. This is a test. This station is conducting a test of the Emergency Broadcast System. This is only a test." Then there are two long beeps, and at 0:58, the text changes to: “This is a test of the Emergency Broadcast System. The broadcasters of your area in voluntary cooperation with federal, state, and local authorities..." 

01.22.96
The tape in this video was donated by another Youtuber, Marionova64. The two of them found this tape and the same video can be found on Marionova's channel, instead under the title "Internal Castle Plexus".

By far the most complex of the tapes, this video shows what appears to be the Internal Plexus of the castle. The player manages to clip through the stained glass window. While urged not to continue, the player continues through the labyrinth of hallways while slowly followed by the Wario Apparition. After travelling to a distorted version of the castle's foyer and then through another hall, the player ends up out into a distorted version of the castle grounds. The player jumps into the water and finds an opening that they try to swim into, but the player's controller disconnects as seen with the "Player 1 No Input" flashing on the bottom left side of the screen. Without any control, Mario is left to drown in the water while the phrase "LEAVE" flashes on screen with the static of the tape getting worse and worse. The tape ends on an error message.

Theorising
The description for the 05.30.97 details and scrapped ending are only located in some builds of the game, and even then, it is usually unaccessable. 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.

Trivia

 * The tapes can be viewed without the VHS filter on Greenio's second channel, Greenio, too.