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