List of Super Mario 64 pre-release and unused content
This is a list of pre-release and unused content for the game Super Mario 64.
32 courses were initially planned for the game, but only 15 of them made it into the final product. In some sketch-ups of the game's early development in Super Mario History, Mario is seen jumping on a piano with the phrase ピアノの上よく(Well on the piano). He is also seen climbing a ladder, swinging around a pole, pushing a door and a block of ice, and crushing a rock with his head. 
During an interview between Satoru Iwata and Shigeru Miyamoto regarding New Super Mario Bros. Wii, Iwata stated that there used to be a multiplayer function that was scrapped from Super Mario 64, likely due to hardware limitations. It was also stated that one could see Mario and Luigi meet in the corridor. This, apparently, inspired the multiplayer function of New Super Mario Bros. Wii.
Iwata: Ever since Mario Bros., you've had your heart set on making a multiplayer Mario game. You've tried each time, but it's never quite come together… Even with Mario 64, it started with Mario and Luigi running around together, didn't it?
In an interview between Iwata and Koichi Hayashida regarding Super Mario 3D Land, it was mentioned during a discussion about the Flagpole that it was once considered to be incorporated into Super Mario 64.
Iwata: The impression the goal pole makes has a big influence over the impression that the game makes. I suppose he thought this was an area that deserved effort.
Mario was originally voiced differently, possessing a screechy, childlike voice rather than his current Italian accent.  Bowser sounded more tiger-like. Big Boo held a key instead of a Power Star inside of him. The purpose of the keys were to unlock a variety of the various doors in Big Boo's Haunt; there was even a "key counter". The upgraded Triple Jump Mario receives after talking to Yoshi in the final game is the same animation used for when Mario enters any level in earlier builds. Jolly Roger Bay used to have music that is similar to the one used in the final game. Also, the sunken ship was much different in the E3 trailer, as it was more modern, had a bridge and a funnel, and was white. The water was very white also.  Mario's Triple Jump resembled Luigi's backward somersault in Super Mario 64 DS. The Thwomp's grunt used to be a deep thunderous "thud". Bowser in the Dark World was only the arena where the player fought Bowser. Blargg was planed to be in the game with it's Super Mario World design and was loaded but not placed in: Lethal Lava Land, Bowser in the Fire Sea and for some odd reason, Wing Mario in the Sky. It has only one animation (in which it jumps out of lava) and its textures are unfinished, meaning it was likely scrapped early in development. Originally, if Mario were to not get on the wooden part of the slide in Tall, Tall Mountain, he wouldn't be led to a dead end, but instead further down a slope that wasn't present in the final game.
Items and objects
Water mines (with graphics identical to spike bombs) were going to be in a water level. Yoshi Egg graphics are stored in the game's code, along with a yellow ! Switch. The presence of Yoshi Eggs implies that Yoshi was originally going to play a more prominent role in the game. There are some unused platforms in the game, such as a flat, checkered platform, resembling the two elevator platforms in Whomp's Fortress. This platform however, does not do anything other than let Mario stand on it. Another unused platform is like the previous one, except it rotates after every couple of seconds. A Cactus was found in the data for Shifting Sand Land, and frames of a flower can also be found in the Lethal Lava Land textures. It seems like both would have been used as background objects. 2 early life counters were used: The first one include a clock-like look, with a clock hand pointing at Mario's health. The second one is similar to the final counter, but it decreased clockwise instead of counter clockwise.
There was originally going to be a Blargg, which is still in the game's data, that was to appear in the Lethal Lava Land, Bowser in the Fire Sea, and Wing Mario Over the Rainbow (as odd as that may sound) courses. In the game, there are small and large bullies, using two models; a Chill Bully appeared in Course 10: Snowman's Land. It too had a small and a large model, but only the large model was used.
One texture in the game is found in Cool, Cool Mountain. It is much like the ice texture that is used, but it has cracks in it. The texture probably used to be covering the water hole where Mama Penguin is. A variation was later used in the remake, as the texture for the breakable ice pond.
In early footage, Bowser had blue eyes instead of red eyes. Also, VL-Tone, the creator of Toad's Tool 64 (a Super Mario 64 level editor), found textures of what looks like a red, black and white trampoline, with a yellow "?" painted on the side. It would most likely have had the same effects as its predecessors.
Sprites and models