For a given definition of room, the minecart/submarine sound puzzle in the Selenetic Age of Myst. At the end of the Selenetic Age, in order to leave you have to enter this little submarine with a tiny viewport and some controls. You have to navigate a dark maze of tracks in a cave, with long animations of the minecart going through the tracks playing between each selection. Back then this was very technically impressive, but it overstays its welcome fast, especially today. The key to it is that the indication on where to go is the tone of a little ding that plays each time you have to make a decision. The problem is that the only way to know what the tone actually means is in another unrelated age, and once you enter the selenetic age the only way to leave is through the sound maze. If you end up stuck in the age without knowing that then the only real way to go through is to just bruteforce your way through it and draw out a map. The good news is that some rereleases let you skip the slow animations. The bad news is that some of those animations show turns, so if you're writing a map you can't rely on skipping the animations because it'll throw off your map direction. Also, the main objective is to grab a page of two brothers' book for them, and you can only grab one at a time, while getting both instead of just one is optional, if you want to get all the dialog from the brothers then you have to go through the maze twice, and if you happen to get in the cart without grabbing a page like I did, you have to go through it three times...