Here is the full list of all 45 Blasphemous achievements. It takes around 25-30 hours to unlock all of the achievements on Windows.
Provoke the meeting between Redento and Cleofás.
Cross the Bridge door in less than 3 hours.
Get 100% of the game.
Save all Kissers of Wounds.
Unlock the ending A.
Use the Righteous Riposte 5 times.
Beat all the arena challenges.
Get all rosary beads.
Unlock the ending B.
Beat His Holiness Escribar.
Beat all bosses without flask consumption.
Achieve the maximum value of flasks.
Achieve the maximum value of rosary bead slots.
Help the Pilgrim reach his final destination.
Get all prayers.
Help Cleofás in his path of redemption.
Talk with all the corpses.
Release all cherubs.
Get all sword hearts.
Achieve the maximum value of fervor.
Bring all the offerings to Lvdovico.
Get all collectibles.
Visit the tomb of The Lady of the Tailed Gown.
Buy all skills from the Mea Culpa shrines.
Achieve the maximum level of the Mea Culpa sword.
Beat Crisanta of the Anointed Blade.
Achieve the maximum value of health.
Beat Quirce, Returned by the Flames.
Beat all types of enemies.
Beat Exposito, Scion of Abjuration.
Get all relics.
Buy all the items of the Candelaria shops.
Bring all the offerings to the Blessed Lord of Salty Shores.
Hatch the Egg of Altasgracias.
Beat Melquíades, The Exhumed Archbishop.
Discover all zones.
Beat Esdras, of the Anointed Legion.
Witness the last moments of Viridiana.
Beat the Our Lady of the Charred Visage.
Execute 5 different enemies.
Beat the Tres Angustias.
Kill 666 enemies.
Beat Perpetua.
Beat Ten Piedad.
Beat the Warden of the Silent Sorrow.