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.
Executed a total of 1000 witches and enemies.
Defeated Harina.
Acquired the Frailty Incense.
Abandoned your mission in favor of the witches.
Collected all the archives.
Purified the witch deity Parushee.
Purified the Witch of Lust.
Defeated a major enemy without taking a hit.
Warmed up Almu, the slug girl.
Collected a total of 20 silver coins.
Defeated Frikka, leader of the thieves.
Purified the witch deity Saora.
Purified Sister Devoir.
Rescued Princess Amelia from a group of witches.