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