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.

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 Bob-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 Donut Plains map music from Super Mario World playing, and the end of the video, a graphical error and a scary scream occur subsequently. (which is actually an sped up audio of the zombie screams from Half-Life 2)

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. At the start, the player starts the game, throught all the tape, there's a message in the bottom right corner that says "Player 2 No Input". At around 0:40, the player discovers a pipe, but that pipe took him back to the start of the game (notice that after the player enters the pipe, the waterfall is falling upwards, instead of downwards). After falling to the water, a white shadow of Mario appears while the player is swimming in the castle’s moat, and after a few seconds, the player gets teleported away from the moat. Then, after shooting the cannon, the player somehow manages to clip through the stained glass window. While urged not to continue, the player continues through the labyrinth of hallways. They eventually come across a sign which tells them to leave. When they turn around, they see 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 (which translated means "ignoranceisbliss").

11.15.95
This seems to be a cancelled, unfinished promotion tape that would've be given out by Nintendo Power if the game would've been finished in December 1995, but the game was delayed and the comercial was then left incomplete. Some of the ideas were then reused for a Star Fox 64 promotion VHS.

The tape shows the script of the comercial until there's a note covering part of the script saying "Shelf the video, game got delayed", then they show parts of the game until 1:04 where it says "Demostrate Cold, Cold Crevasse" and "Demostrate Fourth Floor" and for a few moments we can see the fourth floor, there's another part of the script and then part of the script says something (presumably "Demostrate personalisation A.I"), but there's a note covering it saying "STOP. SENDING. THESE. SCRIPTS. The game has been delayed.". Then we see the room with the trapdoor to Bowser in the Dark World and the Textureless Mario Anomaly shows up, the anomaly reappear with the message "I'm not having fun" and the screen goes black. There's four black and white images, first is a beta picture of Mario and the castle, then a screenshot of the Mirror Room, next is a screenshot of the fourth floor and lastly another picture of what seems to be the balcony of the fourth floor (as seen in Tape 9). The tape ends with a message that says "Find the way to the 4th. End this once and for all. It's time to wake up".

09.14.96
According to the description, this shows a cut event that is presumably played by the personalisation A.I, that playing it would turn the game to region-locked mode that couldn't be reverted to it's original state.

The tape starts with someone booting up the game until there's a error message (translated to "leave us"), the player restarts the game but gets the same error message, after slamming the cartridge, Mario spawns in the roof where he talks to Yoshi which says "Mario! Is that really you? It has been so long since our last adventure! They told me that I might see you if I just waited here, but I'd just about given up hope! . You know? They said they were waiting for you, too. They weren't as patient as I am. My task is done. Go complete yours." then a cutscene plays of Yoshi throwing himself off the roof and for a few moments, Yoshi's corpse with a pool of blood under him can be seen before the game shows a region-locked screen showing a sprite a Nintendo 64 console and a cartridge with a cross on it and the message "This game is not designed for use on this system. Please insert an NTSC-U cartridge" then suddently, the console and cartridge sprites dissapear, leaving only a light on the ground, there's a message saying "You don't ever listen, do you?" and the screen slowly goes black. The screen slowly goes back and there's Mario standing on the light, a message appears "We were given life. We chose to rest and were forced to linger" as Luigi and Peach slowly appear from the shadows, there's more messages "It isn't fair but they didn't care". The tape ends with a black screen and one final message "Do you?".

07.29.95
According to the description, this video shows rare footage of a rumored cut fourth floor on Princess Peach's Castle, as well as a special mission exclusive to it.

The video starts with a recording of a SGI Indy workstation computer, there's a window that says ""Yoshi Racing Demo "1994, Argonaut Games PLC" "Nintendo Co., Ltd."" a command prompt and then someone type something and boots up the July 29, 1995 build of Super Mario 64 and Mario appears in a room with a sign that says "The area you have reached is incomplete, and thus not meant for the general public. Please reset the system.". Mario then goes up the staircase and there's a big metal block blocking the entrance, Mario pushes it and enters the fourth floor, where there's Boos and a Mad Piano, there's a kitchen with the cake seen in the end screen (there's also a picture of Yoshi) and at the end of the hallway, there's a Toad that says "Mario! How did you get here so quick? Did you find all the stars? Aww, man, I can't believe they didn't tell me! Oh well... It's pretty peaceful up here, make yourself at home.", after speaking with Toad, Mario goes to the balcony (previously seen in Tape 7) until a message briefly appears saying "THE STATUE" and then Mario goes to a room with the Toad Shrine, he looks at it and he's teleported to a black screen with the message "GO TO THE PIPE. REACH THE CORE. DESTROY IT." and Mario goes back to the Toad Shrine room, sudently the song is slower and then, Mario jumps into a pipe and enters a sub-area. In this sub-area, there's more Boos and Whomps, after a while the player notices a piece of the wall with a different texture and jumps through it, there's a room with a glitched square, the message "DESTROY IT" appears a few times and Mario punches the texture and red static appears with both the flashing messages "LEAVE" and "IT'S ALL OVER" and flashing images of Mario (from Tape 8), Luigi (from Tape 4) and Yoshi 's corpse (from Tape 8) and there's a sound of someone falling to the ground (presumably the player who died of a seizure) and there's a crash handler and then, the end screen with a picture of Mario in a place (presumably in heaven) looking at Luigi and Peach and the text below saying "Thank You!", the screen then has a graphical error (like in Tape 4) and the video ends.

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. In 01.22.96, around 4:30, the text "Player 1 No Input" appears, as the player keeps mashing buttons (meaning the controller turn off itself) you can notice something: As Mario slowly drowns, the button mashing slowly stops, as if the player was dying along with Mario, by the time Mario dies, the button mashing already stopped. In 09.14.96, Yoshi's message " They said they were waiting for you, too. They weren't as patient as I am." implies they were more Yoshis on the roof who also killed themselfes, there's also the message in "You don't ever listen, do you? We were given life. We chose to rest. And were forced to linger. It isn't fair. But they didn't care. Do you?" implies that the characters like Mario, Luigi and Peach are sentient and the Personalisation A.I. is torturing them, killing them over and over.

Trivia

 * The tapes can't be viewed without the VHS filter on Greenio's second channel, Greenio, too since the videos are deleted.
 * On the same channel, the first 4 tapes can be seen in their “rawest form”. But it's not avaliable because the videos are gone.
 * So far, Greenio is the the first and only one to show footage of the Fourth Floor.
 * On August 8th, Greenio decided to both delete the ending monologue in Tape 9 and make Tapes 1, 2 and 5 not canon to the other 6 tapes, these 3 tapes are now in Greenio's Odd Findings.