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