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