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.
Find all the notes.
Kill all enemies as the Knight.
Collect all the Pain Crystals.
Complete the castle scene without taking damage.
Complete the fire scene without taking damage.
Complete the swamp scene without taking damage.
Talk to the cats when their sibling is alive.
Finish the final scene.
Complete the Snow scene without taking damage.
Discover what's in the attic.
Listen to all the rabbit's comments.
Discover the fountain.
Listen to all the Storyteller's tales.
Kill all jumpers.
Complete the Slime Pit scene without taking damage.
Host a Tea Party!
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