Here is the full list of all 45 Blasphemous achievements. It takes around 25-30 hours to unlock all of the achievements on Windows.
Unlock the ending B.
Beat His Holiness Escribar.
Beat Crisanta of the Anointed Blade.
Beat all types of enemies.
Execute 5 different enemies.
Beat Quirce, Returned by the Flames.
Beat Exposito, Scion of Abjuration.
Beat Melquíades, The Exhumed Archbishop.
Beat Esdras, of the Anointed Legion.
Kill 666 enemies.
Witness the last moments of Viridiana.
Beat the Our Lady of the Charred Visage.
Beat the Tres Angustias.
Beat Perpetua.
Beat Ten Piedad.
Beat the Warden of the Silent Sorrow.
Unlock the ending A.
Release all cherubs.
Talk with all the corpses.
Beat all the arena challenges.
Get all prayers.
Get all relics.
Get all rosary beads.
Get all collectibles.
Get all sword hearts.
Discover all zones.
Achieve the maximum value of health.
Achieve the maximum value of fervor.
Achieve the maximum level of the Mea Culpa sword.
Achieve the maximum value of flasks.
Achieve the maximum value of rosary bead slots.
Use the Righteous Riposte 5 times.
Visit the tomb of The Lady of the Tailed Gown.
Bring all the offerings to Lvdovico.
Help Cleofás in his path of redemption.
Help the Pilgrim reach his final destination.
Bring all the offerings to the Blessed Lord of Salty Shores.
Save all Kissers of Wounds.
Buy all the items of the Candelaria shops.
Hatch the Egg of Altasgracias.
Buy all skills from the Mea Culpa shrines.
Provoke the meeting between Redento and Cleofás.
Beat all bosses without flask consumption.
Cross the Bridge door in less than 3 hours.
Get 100% of the game.