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.
Abandoned your mission in favor of the witches.
Purified Princess Poeme.
Collected all the archives.
Purified the witch deity Parushee.
Purified the Witch of Lust.
Collected a total of 20 silver coins.
Defeated Frikka, leader of the thieves.
Defeated a major enemy without taking a hit.
Warmed up Almu, the slug girl.
Purified the witch deity Saora.
Purified Sister Devoir.
Rescued Princess Amelia from a group of witches.