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