The enemy Blargg from Super Mario World is found in the game's code, but it's model and programming are unfinished. It has an animation for jumping out of lava, but doesn't do anything else.

If you allow Mario to fall asleep (by remaining idle for an extended period of time) for long enough, he'll start sleep-talking about spaghetti and ravioli, two Italian foods.

In 1997, Nintendo released a Japan-exclusive version of Super Mario 64 which had Rumble Pak support. It also included the English voice acting which the original Japanese version didn't have, and fixed some glitches. This version would later see an international release when Super Mario 64 was included in Super Mario 3D All-Stars.

There is an unused animated Yoshi egg texture in the game's data, suggesting that Yoshi was going to play a bigger role in the game, similar to Super Mario World.

In the original Japanese version, if the player runs to where a key will land after defeating Bowser in the Dark World or Fire Sea, presses C-Up and looks somewhere, Mario will keep looking in that direction during the key collection cutscene.

In the December 1997 issue of The64Dream, Miyamoto stated that Super Mario 64 2 would have made Luigi a full part of the game, and that if he was really popular, then the box for Super Mario 64 2 would be green.

If you jump up and down in a shallow pool of water, you can occasionally see a fish jump out of the water with you.

There is a cancelled sequel for Super Mario 64, commonly called "Super Mario 64 2" or "Super Mario 128" (not to be confused with the tech demo of the same name) for the failed N64 DD. Only one demo was ever made, but was never shown to the public. The only information known about the game is that Luigi was going to feature in it, and co-operative play was a speculated feature. Since these two elements feature in Super Mario 64 DS, it's possible that other elements from Super Mario 64 2 were incorporated into Super Mario 64 DS.

MIPS, the rabbit in the castle basement, is named after the MIPS (Microprocessor without Interlocked Pipeline Stages) microprocessor. The Nintendo 64's CPU runs on a MIPS Microprocessor, so the name was chosen for the rabbit.

In early development of the game when Nintendo were working on character movement and camera angles, they only had two characters; MIPS the rabbit and Mario. MIPS was planned to be just a testing dummy, but made it into the final game because they didn't want to part with him.

When you catch MIPS the bunny in the castle basement, he references Alice In Wonderland. Just like the White Rabbit, he says he's late. Then he says says he'll give you a star, but he has an important date to get to.

The penguin found during the 3rd star of the "Cool, Cool Mountain" level changes after 120 stars are found. After obtaining all the stars, the penguin is found much fatter than before from not doing races lately. He can be raced again, but there is no additional reward for beating him.

There are murals on the pillars in Bowser in the Sky depicting the original fight with Bowser from Super Mario Bros.

In the Japanese version of the original game, the painting for Jolly Roger Bay originally had a blue frame with bubbles. This was changed to a pirate ship with a gold frame in the international release of the original game. In the Nintendo DS remake, the painting reverted back to the original blue-framed form.

Boo's creepy laugh is actually just Bowser's laugh sped up.

Although the Headless Snowman is a minor character in his few appearances, he received some publicity in the form of a Nintendo Power joke published around the time of the main circulation of the "L is Real 2401" Super Mario 64 rumors.

In Volume 107 of Nintendo Power, in the April Fool's-themed "April News Briefs" segment, a "Luigi 64" article is present, where Nintendo states that Luigi fans had been campaigning to have the character in his very own game, and the company's response was to create a hoax upcoming game known as "Headless Snowman 64". This game was apparently intended to satisfy fans of the "second bananas" by featuring a cast of both well-known and obscure Nintendo characters, with the obscure characters including the Wave Race 64 announcer, "random audience members from Super Punch-Out!!", "the frogs in the meadow" from Diddy Kong Racing, and the Headless Snowman himself. Additionally, the game would supposedly contain some non-Nintendo characters such as "that bald guy from Blast Corps," and "the bikini woman in Cruis'n USA." Humorously, this never-made game was not going to feature Luigi, with a developer comment at the end of the article confusing him for "one of the civilian women in GoldenEye 007".

In a 1996 interview with Shigeru Miyamoto published in Super Mario 64's first Japanese strategy guides, he revealed that Mario's running animation, speed and movements in that game were influenced by Arale, the main protagonist of the 1980 Akira Toriyama manga/anime "Dr. Slump":


However, Dr. Slump's influence throughout the Mario series could trace back even further. Some particular examples from Mario games include:

• His running speed, animation, the Racoon and Tanooki Suits from Super Mario Bros. 3
• The Wing Cap from Super Mario 64
• The Cat Suit from Super Mario 3D World

Even traits of Mario's happy cartoonish personality, his short stature and gloves, and blue-red-overalls color scheme bear enough similarities that they all could have been taken from Arale's appearances and other elements throughout Dr. Slump. Despite this, outside of Miyamoto's comment, these connections are not known to have been elaborated on by any other employee from Nintendo.

In an interview with Satoru Iwata and Shigeru Miyamoto, it was revealed that an early, experimental build of the game had split-screen multiplayer, with Mario and Luigi as playable characters.

The game's planned multiplayer mode ended up being reworked into a Mario Bros.-style minigame thanks to the Nintendo 64's technical limitations making the split-screen concept unfeasible. However, in February of 1996 (just a month before E3 of that year), both multiplayer mode and Luigi were removed, in part because the Nintendo 64 was bundled with only one controller. These statements are corroborated by findings from the Gigaleak, a massive content leak of internal data from Nintendo in 2020 that included early assets from Super Mario 64. Among the leaked material was a model and textures for Luigi and sprites for "1P" and "2P" icons. Luigi's model is dated June 20, 1995, while the icons use the same generic font seen in the Shoshinkai demo from November of that year, rather than the custom font seen in both the E3 1996 demo and the final release.

The title of "first 3D platformer" is often erroneously given to either 1996's Super Mario 64 or 1995's Jumping Flash!. Despite this, neither game can factually claim that title, with 1990's Alpha Waves being the true owner of the title according to Guinness World Records.

Additionally, 1984's I, Robot - while primarily a shooting game - did feature 3D platforming segments.

In the castle courtyard in Super Mario 64, there is a plaque to a power star with an illegible name written below, often interpreted as either "Eternal Star" or "L is Real 2401" - with the latter being more popular for how it could be seen as a cryptic hint towards unlocking Luigi.

In a poetic coincidence, the source code leak that revealed Luigi's scrapped model would be found 24 years and 1 month after Super Mario 64's release.