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