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