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