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