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.
Witness the last moments of Viridiana.
Provoke the meeting between Redento and Cleofás.
Save all Kissers of Wounds.
Cross the Bridge door in less than 3 hours.
Talk with all the corpses.
Unlock the ending A.
Get 100% of the game.
Beat His Holiness Escribar.
Get all prayers.
Discover all zones.
Beat Crisanta of the Anointed Blade.
Beat all types of enemies.
Release all cherubs.
Get all collectibles.
Get all rosary beads.
Beat all the arena challenges.
Buy all skills from the Mea Culpa shrines.
Achieve the maximum level of the Mea Culpa sword.
Achieve the maximum value of flasks.
Achieve the maximum value of fervor.
Achieve the maximum value of rosary bead slots.
Achieve the maximum value of health.
Beat Quirce, Returned by the Flames.
Get all sword hearts.
Buy all the items of the Candelaria shops.
Help Cleofás in his path of redemption.
Beat Melquíades, The Exhumed Archbishop.
Beat Exposito, Scion of Abjuration.
Bring all the offerings to the Blessed Lord of Salty Shores.
Get all relics.
Help the Pilgrim reach his final destination.
Bring all the offerings to Lvdovico.
Beat Esdras, of the Anointed Legion.
Use the Righteous Riposte 5 times.
Hatch the Egg of Altasgracias.
Beat the Tres Angustias.
Kill 666 enemies.
Beat Ten Piedad.
Beat Perpetua.
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.