Here is the full list of all 29 INMOST achievements.
Zero deaths as the wanderer.
Play without collecting any pain.
Gain all the achievements.
Talk to the cats when their sibling is dead.
Talk to the cats when their sibling is alive.
Listen to all the Storyteller's tales.
Collect all the Pain Crystals.
Finish the final scene.
Kill all enemies as the Knight.
Complete the Snow scene without taking damage.
Discover what's in the attic.
Listen to all the rabbit's comments.
Discover the fountain.
Kill all jumpers.
Find all the notes.
Listen to the Storyteller's first tale.
Complete the Slime Pit scene without taking damage.
Host a Tea Party!
Get the Cookies.
Complete the swamp scene without taking damage.
Complete the fire scene without taking damage.
Enter the mines.
Find the rabbit.
Complete the castle scene without taking damage.
Defeat the first hunter.
Save the cat from the hunter
Finish the Old Man Scene
Find a hidden Pain Crystal
Finish the Girl Scene