As this has been unrejected, I'd like to explain the category of this run.
In Myst, the aim of the game is to complete and use linking books. There are several such books in the game, but three are particularly tied to the plot: Sirrus's, Achenar's, and Atrus's. Sirrus's and Achenar's books start missing five pages each, whereas Atrus's is missing only one.
At the start of the game, the pages in Sirrus's and Achenar's books are hard to access (you get one of each in each of the four main levels), whereas the missing page for Atrus's book is in the hub world (and thus easy to access), but hidden behind a specific sequence of actions (that is intended to be determined via clues in two of the main levels, rather than known at the start of the game). These actions are always the same, and can be performed regardless of whether the character knows what they are or not. As such, this TAS skips all the levels of the game but the hub world, and starts off by just getting the missing page in Atrus's book.
The game also requires you to find the linking books before you can add pages to them. Sirrus's and Achenar's books are trivial to find, but Atrus's (and one of the pages for Sirrus's and for Achenar's books) are hidden behind a combination lock (that's the lock that the TAS takes so long entering). When four of the five pages are added to Sirrus's or Achenar's books, they tell you how to determine the combination. However, the combination is also always the same, and can be entered even if the character doesn't know what it is, so the TAS, after obtaining Atrus's page, just skips directly to obtaining Atrus's book.
Finally, you get the best ending for completing and using Atrus's book, and bad endings for merely completing Sirrus's or Achenar's books, or using Atrus's book before it's complete. (The bad endings aren't considered wins by most Myst players, but rather nonstandard game overs.) As such, the TAS only needs to fetch Atrus's book and the missing page for it, and it completes the game with the best ending.
A 100% run would retrieve or locate all 11 missing pages, but would only use 9 of them (4 for Sirrus's book, 4 for Achenar's book, and 1 for Atrus's book that's used in a cutscene after losing control). (The last two pages cannot be used because that would lead to a bad ending.) This submitted run is any%, best ending (in fact, it's a low% for the best ending, with a somewhat major sequence break due to the use of codes that have not been revealed in-game). An any%, bad ending run would be somewhat faster if it aimed for Atrus's bad ending (as it would be the same without obtaining Atrus's page); it would be considerably slower if it aimed for Achenar's or Sirrus's bad endings, as that would require completing most of the game to gather the pages. A 100% would be longer still, due to needing to get both of those sets of pages; it would also be quite repetitive, because doing so requires moderately large amounts of backtracking / repeating areas.
The most entertaining category for the game would definitely involve fetching four pages for at least one of Achenar's and Sirrus's books, which is meant to be required in order to locate Atrus's. You could argue for an "unspoiled" category, where the character does not use information that they haven't learned ingame, to enforce this, but that's a bit of a stretch and hard to judge objectively. Merely doing everything with Atrus's book, though, causes the TAS to not actually visit any of the levels, as everything required is in the hub world.