Complete the indicated task to unlock the corresponding ending. To increase your morality, make good decisions and spare downed monsters. To decrease your morality, do the opposite.

A ending: Spare Anne with good morality.
B ending: Spare Anne with bad morality.
C ending: Kill Anne with good morality.
D ending: Kill Anne with bad morality.
E ending: Let Anne kill you during the finale.
F ending: Complete the game, then during your second playthrough, complete the "Digging up the past" side quest.
Secret Ending 1: Complete the game, then during your second playthrough complete the "Digging Up the Past" side quest before completing the game again.
Secret Ending 2: Die during the final encounter.