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