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