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