Here is the full list of all 45 Blasphemous achievements. It takes around 25-30 hours to unlock all of the achievements on Windows.
Talk with all the corpses.
Use the Righteous Riposte 5 times.
Get all prayers.
Get 100% of the game.
Release all cherubs.
Unlock the ending A.
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.
Beat Perpetua.
Achieve the maximum value of flasks.
Achieve the maximum value of fervor.
Get all rosary beads.
Buy all skills from the Mea Culpa shrines.
Achieve the maximum level of the Mea Culpa sword.
Bring all the offerings to the Blessed Lord of Salty Shores.
Get all relics.
Beat all the arena challenges.
Unlock the ending B.
Beat His Holiness Escribar.
Beat all types of enemies.
Discover all zones.
Beat Crisanta of the Anointed Blade.
Help Cleofás in his path of redemption.
Get all collectibles.
Buy all the items of the Candelaria shops.
Visit the tomb of The Lady of the Tailed Gown.
Achieve the maximum value of rosary bead slots.
Achieve the maximum value of health.
Beat Quirce, Returned by the Flames.
Get all sword hearts.
Beat Exposito, Scion of Abjuration.
Execute 5 different enemies.
Beat Melquíades, The Exhumed Archbishop.
Help the Pilgrim reach his final destination.
Beat Esdras, of the Anointed Legion.
Bring all the offerings to Lvdovico.
Hatch the Egg of Altasgracias.
Witness the last moments of Viridiana.
Beat the Tres Angustias.
Kill 666 enemies.
Beat the Our Lady of the Charred Visage.
Beat Ten Piedad.
Beat the Warden of the Silent Sorrow.