Here is the full list of all 45 Blasphemous achievements. It takes around 25-30 hours to unlock all of the achievements on Windows.
Cross the Bridge door in less than 3 hours.
Talk with all the corpses.
Provoke the meeting between Redento and Cleofás.
Unlock the ending A.
Get 100% of the game.
Get all rosary beads.
Beat all the arena challenges.
Unlock the ending B.
Beat His Holiness Escribar.
Discover all zones.
Beat Crisanta of the Anointed Blade.
Beat all types of enemies.
Buy all skills from the Mea Culpa shrines.
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 flasks.
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.
Execute 5 different enemies.
Beat Esdras, of the Anointed Legion.
Bring all the offerings to Lvdovico.
Use the Righteous Riposte 5 times.
Hatch the Egg of Altasgracias.
Witness the last moments of Viridiana.
Beat the Tres Angustias.
Beat Perpetua.
Beat Ten Piedad.
Kill 666 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.
Beat all bosses without flask consumption.