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.
Cross the Bridge door in less than 3 hours.
Unlock the ending B.
Get 100% of the game.
Unlock the ending A.
Beat His Holiness Escribar.
Beat all bosses without flask consumption.
Beat Crisanta of the Anointed Blade.
Talk with all the corpses.
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.
Get all rosary beads.
Achieve the maximum value of flasks.
Achieve the maximum value of rosary bead slots.
Save all Kissers of Wounds.
Achieve the maximum value of health.
Beat all the arena challenges.
Beat Quirce, Returned by the Flames.
Beat all types of enemies.
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.
Witness the last moments of Viridiana.
Beat Exposito, Scion of Abjuration.
Buy all the items of the Candelaria shops.
Discover all zones.
Beat Esdras, of the Anointed Legion.
Bring all the offerings to Lvdovico.
Hatch the Egg of Altasgracias.
Beat the Tres Angustias.
Beat Perpetua.
Visit the tomb of The Lady of the Tailed Gown.
Beat the Our Lady of the Charred Visage.
Kill 666 enemies.
Beat Ten Piedad.
Execute 5 different enemies.
Use the Righteous Riposte 5 times.
Beat the Warden of the Silent Sorrow.