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