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