Finish the game in Hard Mode.

Complete all puzzles.

Complete all rubbings.

Upgrade Dante's health to maximum

Gain a 100% completion rank on all missions (difficulty doesn't matter)

Open all of the Secret Doors

Completed Episode 21.

Completed Episode 19.

Find all of the Keys

Complete Furnace of Souls without taking damage from the furnace

Complete the Mystery.

Completed Episode 17.

Completed Episode 16.