Here is the full list of all 45 Blasphemous achievements. It takes around 25-30 hours to unlock all of the achievements on Windows.
Beat all bosses without flask consumption.
Get all rosary beads.
Get 100% of the game.
Save all Kissers of Wounds.
Talk with all the corpses.
Provoke the meeting between Redento and Cleofás.
Get all prayers.
Cross the Bridge door in less than 3 hours.
Beat Perpetua.
Unlock the ending A.
Beat all the arena challenges.
Get all sword hearts.
Unlock the ending B.
Beat His Holiness Escribar.
Beat Crisanta of the Anointed Blade.
Beat all types of enemies.
Get all collectibles.
Visit the tomb of The Lady of the Tailed Gown.
Release all cherubs.
Bring all the offerings to the Blessed Lord of Salty Shores.
Get all relics.
Achieve the maximum value of rosary bead slots.
Help the Pilgrim reach his final destination.
Buy all skills from the Mea Culpa shrines.
Achieve the maximum level of the Mea Culpa sword.
Achieve the maximum value of flasks.
Achieve the maximum value of health.
Bring all the offerings to Lvdovico.
Hatch the Egg of Altasgracias.
Beat Quirce, Returned by the Flames.
Achieve the maximum value of fervor.
Help Cleofás in his path of redemption.
Witness the last moments of Viridiana.
Beat Melquíades, The Exhumed Archbishop.
Buy all the items of the Candelaria shops.
Execute 5 different enemies.
Beat Exposito, Scion of Abjuration.
Discover all zones.
Beat Esdras, of the Anointed Legion.
Beat the Our Lady of the Charred Visage.
Beat the Tres Angustias.
Kill 666 enemies.
Beat Ten Piedad.
Use the Righteous Riposte 5 times.
Beat the Warden of the Silent Sorrow.