Here is the full list of all 26 Myst achievements.
Found a way back from Mechanical.
Solved the gear puzzle inside of the clocktower.
Found a way back from Selenitic.
Solved the generator power puzzle.
Fill up all of the shelf space for a page type.
Found a way back from Stoneship.
Found a way back from Channelwood.
Returned to Myst Island from D'ni.
Achieved the good ending within two minutes.
Achieved the bad ending with Atrus.
Achieved bad ending with Sirrus.
Achieved bad ending with Achenar.
Achieved the good ending without inserting a single red or blue page.
Achieved the good ending.
Solved the fireplace puzzle.
Opened the safe in the cabin.
Solved the piano puzzle in a single try.
Viewed some dated constellations.
Raised the sunken ship.
Rode the tree to the highest position.
Found the white page.
Found Sirrus' message to Achenar.
Solved the compass puzzle.
Found the skeleton in the Mechanical Age.
Made it through the maze in Selenitic without pressing "backtrack" on a randomized playthrough.
Achieved one of the brothers' endings while on a randomized playthrough.