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