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