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.
Unlock the ending B.
Provoke the meeting between Redento and Cleofás.
Cross the Bridge door in less than 3 hours.
Get 100% of the game.
Unlock the ending A.
Beat His Holiness Escribar.
Buy all skills from the Mea Culpa shrines.
Talk with all the corpses.
Beat all the arena challenges.
Get all rosary beads.
Get all prayers.
Release all cherubs.
Get all collectibles.
Achieve the maximum value of rosary bead slots.
Get all sword hearts.
Beat Crisanta of the Anointed Blade.
Achieve the maximum value of flasks.
Achieve the maximum level of the Mea Culpa sword.
Achieve the maximum value of health.
Save all Kissers of Wounds.
Beat Quirce, Returned by the Flames.
Beat all types of enemies.
Achieve the maximum value of fervor.
Bring all the offerings to the Blessed Lord of Salty Shores.
Get all relics.
Help the Pilgrim reach his final destination.
Help Cleofás in his path of redemption.
Beat Melquíades, The Exhumed Archbishop.
Beat Exposito, Scion of Abjuration.
Buy all the items of the Candelaria shops.
Discover all zones.
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.
Beat Perpetua.
Kill 666 enemies.
Beat Ten Piedad.
Use the Righteous Riposte 5 times.
Execute 5 different enemies.
Visit the tomb of The Lady of the Tailed Gown.
Beat the Our Lady of the Charred Visage.
Beat the Warden of the Silent Sorrow.