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