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