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