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