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