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