Achieved bad ending with Achenar.

Found a way back from Mechanical.

Solved the gear puzzle inside of the clocktower.

Viewed some dated constellations.

Achieved the good ending.

Achieved one of the brothers' endings while on a randomized playthrough.

Found a way back from Channelwood.

Solved the generator power puzzle.

Found the skeleton in the Mechanical Age.

Solved the piano puzzle in a single try.

Achieved the bad ending with Atrus.

Opened the safe in the cabin.

Found the white page.

Achieved bad ending with Sirrus.

Made it through the maze in Selenitic without pressing "backtrack" on a randomized playthrough.

Fill up all of the shelf space for a page type.

Returned to Myst Island from D'ni.

Found a way back from Selenitic.

Found Sirrus' message to Achenar.

Rode the tree to the highest position.

Achieved the good ending within two minutes.

Solved the fireplace puzzle.

Raised the sunken ship.

Achieved the good ending without inserting a single red or blue page.

Solved the compass puzzle.

Found a way back from Stoneship.

Arrive on Rime.

Accidentally gas yourself.

Trigger the aurora in the skies of Rime.

Discover the secrets of the Rime Age.