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