Here is the full list of all 25 Morbid: The Seven Acolytes achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Slay an Acolyte, without taking any damage
Fall 100 times
Defeat the Acolytes and Liberate Mornia
Defeat Inquisitor Odius, the Scholar of Hate
Discover Cathedral of Wrath
Discover Necropolis
Defeat Maestro Bibé, the Anxious Prodigy
Unlock all Blessings
Discover Concert Hall
Defeat Vulgus Calia, the Mass of Terror
Discover City of Yortael
Defeat Bile Toad Putrus, the Spawn of Disgust
Discover Felfields
Defeat King Cornelius, the Heir of Regret
Discover Tomb of the King
Upgrade a Blessing to the maximum level
Find the Broccoliath body and the Blader from Grimwald’s Grove.
Defeat Lady Tristana, Mother Grief
Kill 50 Elite enemies
Discover Gardens of Mornia
Discover Grimwald's Grove
Discover Village of Aer'Abuh
Defeat Lorn the Blind, the Lord of Loneliness
Discover Caverns of Solitude
Discover The Cursed Hamlet