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