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