Here is the full list of all 25 Chants of Sennaar achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Finish the game (or not?)
Reaching the real end of the game
See the captured monster in the Laboratories
Meet Bards in the Library
Meet a Serf in the Abbey
Attend the Bards' show in the Fortress
Leave the Armory with the wrong disguise once the Call is made
See the Great Door of the Abbey open
Rebuild all links in the game
Visit the revived Abbey Garden
Validate all glyphs in the game
Activate all Terminals
Reach Exile
Rebuild half of the links
Take a trip in the Alchemists' cable car
Reach the Galleries
Validate half of the game's glyphs
Winning at both games in the Gardens
Reach the Garden
Rebuild a first link
Reach the Frontier
Discover the Preacher's corpse
Ring the Abbey bell three times
Reach the Abbey
Fill in the Journal's first page