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