Here is the full list of all 29 INMOST achievements.
Listen to all the rabbit's comments.
Gain all the achievements.
Kill all enemies as the Knight.
Zero deaths as the wanderer.
Play without collecting any pain.
Talk to the cats when their sibling is dead.
Find all the notes.
Complete the Snow scene without taking damage.
Complete the Slime Pit scene without taking damage.
Complete the swamp scene without taking damage.
Complete the fire scene without taking damage.
Complete the castle scene without taking damage.
Finish the final scene.
Discover what's in the attic.
Discover the fountain.
Collect all the Pain Crystals.
Talk to the cats when their sibling is alive.
Listen to all the Storyteller's tales.
Kill all jumpers.
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