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