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