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