Here is the full list of all 38 Moss achievements.
Destroy two or more Screecher enemies with a controlled Ticker.
Find a low-hanging path to the town pub.
Finish the first book of Moss.
Defeat the serpent Sarffog.
Climb to the castle bridge alongside Quill.
Break everything within the town pub that can be broken.
Collect a large amount of Relic Dust.
Enter the Abandoned City alongside Quill.
Enter the Namelhook Mining cave alongside Quill.
Destroy a Forged enemy with an aerial attack.
Use your power as a Reader to break many objects.
Destroy a Forged enemy with a controlled Scorcher.
Unlock the path to the Mire Temple's altar room.
Light the torches of the Knights of the Sun.
Take control over many Forged enemies.
Collect a small amount of Relic Dust.
Guide Quill to destroy multiple thorn patches.
Use Quill's sword to cut down a lot of grass.
Give Quill a high five.
Use a Screecher to unlock the path forward.
Enter the Mire Temple alongside Quill.
Defeat the Screechers first encountered in the Mire.
Use your power as a Reader to heal Quill for the first time.
Startle Quill from behind.
Annoy Quill by delaying the adventure.
Follow the Starthing and Quill into the impassable Mire.
Enter the Clearing alongside Quill.
Discover your first Forgotten Piece.
Collect all of the forgotten fragments.
Collect all of the Relic Dust.
Rescue Argus without a single death.