Full list of all 56 Lords Of The Fallen achievements. It takes around 60-80 hours to unlock all of the achievements in the base game on Windows.
The base game contains 46 achievements, and there is 1 DLC pack containing 10 achievements.
Defeated First Warden
Found a note that someone left behind
Found 60 audio notes
Got 12 special weapons
Collected 20 armor sets
Completed the game as Cleric
Completed the game as Rogue
Completed the game as Warrior
Defeated a Boss without taking damage
Collected 9 Tyrant Hearts
Collected 25 Human Skulls
Defeated the Worshiper
Defeated the Annihilator
Defeated the Commander
Defeated the Guardian
Defeated the Champion
Defeated the Infiltrator
Defeated the Beast
Defeated Lost Brothers
Met the Blacksmith
Looted all Treasure Chambers
Completed all Proving Grounds
Completed all Infinite Voids
Unlocked all spells for one class
Bought your first Attribute or Spell Point
Died for the first time
Retrieved lost experience by collecting your ghost
Upgraded the Health Potions
Defeated a boss with at least 20000 unspent experience
Let the boss destroy the statue during fight
Collected all weapon types
Killed all types of enemies
Kicked an enemy into his death
Met Antanas
Entered the Rhogar realm
Met Adyr
Found the Gauntlet
Purified the sword of the unlucky grave robber
Throw a corpse down the bottomless pit in Catacombs
Cut off Monk's arm
Entered 15 secret rooms
Killed the First Warden with the Warden Greatsword
Showed mercy to an imprisoned monster
Led humans to victory
Led Rhogar to victory
Bring balance to both realms
Found all eight audio notes in the Ancient Labyrinth
Just in case you picked up a shielding map
Manipulated the Keeper's magic schools
Plundered all four resting places
Defeated the Keeper
Chose a perfectly fitting armor
Killed 40 ghosts in the Ancient Labyrinth
Met a strange person in a strange place
Defeated the Judge with a weapon dropped by the Keeper
Defeated the Keeper after changing his initial magic school to the fire type