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