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