Here is the full list of all 15 Minoria achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Purified Princess Poeme.
Defeated Harina.
Acquired the Frailty Incense.
Collected all the archives.
Defeated Frikka, leader of the thieves.
Purified the Witch of Lust.
Abandoned your mission in favor of the witches.
Purified the witch deity Parushee.
Collected a total of 20 silver coins.
Executed a total of 1000 witches and enemies.
Rescued Princess Amelia from a group of witches.
Purified Sister Devoir.
Warmed up Almu, the slug girl.
Purified the witch deity Saora.
Defeated a major enemy without taking a hit.