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