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