Here is the full list of all 16 Mortal Manor achievements.
Defeated the final boss for the first time.
Beat the game on Hard mode.
100% complete the map.
100% get all the weapons.
100% get all the relics
Beat the game with any randomized element.
100% get every trail.
100% defeat every enemy.
Witness the bad ending.
Witness the incomplete ending.
Witness the flooded ending.
Witness the bad Submariner ending.
Witness the final ending.
Beat the game on Hard with randomized items, weapons, relics, and enemy types.
Beat the game with the Submariner.
Witness the "best" ending.