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