Here is the full list of all 15 The Devourer: Hunted Souls achievements.
Finish the tutorial
Decide to spare Lily
Decide to burn Lily
Find the key that was mentioned by "John"
Unlock the basement with the key
Unlock John's notebook
Touch the altar and open the hidden location in the cave
Avoid taking damage as Aurora
Pickup a paranormal item while using Hideyoshi's vision
Come back to life after surviving the creature's hunger
Put Lily's soul on the altar and set her free
Find all rune fragments needed and assemble the rune on your workbench
Read the note the doll girl wrote for you
Research about the backstory of an item
Finish a Halloween Event succesfully.