A member of the Super Mario 64 speedrunner community has managed to solve a riddle that is 28 years old. In the game, on the Cool, Cool Mountain level, there is a hut with a door that you can exit through, but not enter. The developers did this because the wooden house is the finish point that must be reached to complete the level.
However, community member Alexpalix1 managed to get through the door, although it didn't improve his speedrun score. YouTuber pannenkoek2012 explained how he managed to do it.
Why was it so difficult?
Doors in Super Mario 64 serve as a trigger for loading a new area of the game level. In the Cool, Cool Mountain level, after going down the hill, the player passes through a door in a hut, thereby activating a script to load a new game area and unload the one already completed.
Because of this, there is no point in simply "pushing" the character model through the door, as speedrunners do in other games, because the game area simply won't load.
To ensure that players don't cheat and make it all the way through, the hitbox of the door was moved inside the hut so that the player's model doesn't reach it - even close to the visible door.
But the players didn't give up, there is a big mother penguin standing next to the hut, and if you bring it to the door and get between it and the door, then hypothetically the penguin model should "push" the Mario model to the door so that he can interact with it and pass through.
And it partially worked, the Mario model did indeed get within the range of the door, but because the trigger for loading a new play area had not yet been triggered, Mario simply fell behind the textures.
The game code doesn't allow for character interaction with objects when falling, so Mario just flew past the door. After that, the community calmed down and recognized that this door could really only be passed in one direction - outward.
However, Alexpalix1 managed to get through the door, and he needed to know the game's code and just one shot.
Nintendo has developed several states for Mario. Falling is a state that starts the moment Mario comes off any surface.
Walking is self-explanatory. But there is also a turn animation, when Mario changes the direction of his movement. And the code assumes that the walking state will start immediately after the turn animation ends.
Alexpalix1 brought the mother penguin to the door and performed a mid-air turn right between her and the door, when the turn state ended, Mario was literally in a walking state near the door for one frame, even though he was in mid-air. However, this was enough for the script to work and Mario walked through the door and inside.
It's all very cool, but Alexpalix1's trick takes more time than it takes to complete the level in a classic way. Therefore, it will not create any fundamental changes in the discipline of speedrunning Super Mario 64.