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