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.
Cross the Bridge door in less than 3 hours.
Save all Kissers of Wounds.
Get 100% of the game.
Provoke the meeting between Redento and Cleofás.
Unlock the ending A.
Buy all skills from the Mea Culpa shrines.
Get all rosary beads.
Get all collectibles.
Achieve the maximum value of rosary bead slots.
Get all prayers.
Release all cherubs.
Beat all the arena challenges.
Get all sword hearts.
Buy all the items of the Candelaria shops.
Talk with all the corpses.
Visit the tomb of The Lady of the Tailed Gown.
Help the Pilgrim reach his final destination.
Bring all the offerings to Lvdovico.
Achieve the maximum level of the Mea Culpa sword.
Achieve the maximum value of flasks.
Help Cleofás in his path of redemption.
Bring all the offerings to the Blessed Lord of Salty Shores.
Get all relics.
Unlock the ending B.
Beat His Holiness Escribar.
Beat Crisanta of the Anointed Blade.
Achieve the maximum value of health.
Hatch the Egg of Altasgracias.
Achieve the maximum value of fervor.
Beat Exposito, Scion of Abjuration.
Beat all types of enemies.
Beat Quirce, Returned by the Flames.
Beat Melquíades, The Exhumed Archbishop.
Discover all zones.
Beat Esdras, of the Anointed Legion.
Witness the last moments of Viridiana.
Beat the Our Lady of the Charred Visage.
Execute 5 different enemies.
Kill 666 enemies.
Beat the Tres Angustias.
Beat Perpetua.
Use the Righteous Riposte 5 times.
Beat Ten Piedad.
Beat the Warden of the Silent Sorrow.