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