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