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