Here is the full list of all 12 Archaica: The Path of Light achievements.
Activate Stone Keys in 10 levels.
Find and activate all Megaliths.
Activate all Lightwells.
Find and collect the Dark Crystal for the Almanach.
Put the Goddess of Fire into a deep slumber.
Complete 20 levels by finding all collectibles.
Collect 15 Cells.
Complete the Initiation Ring and activate the Realmgate.
Find and activate the Primal Well in the Desert City.
Collect 15 devices for the Almanach.
Complete one of the Great Realms without using a hint.
Collect chronicles from 3 realms.