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