Unlock the following characters by performing the corresponding tasks:

CHARACTER - HOW TO UNLOCK
Aeon - Connect Wii to DS with Order of Ecclesia or beat Aeon's story twice
Golem - Complete Grant's storyline
Grant - Complete Sypha's storyline
Maria - Complete Alucard's storyline
Shanoa - Connect Wii to DS with Order of Ecclesia OR Complete True Story Mode with her
Sypha - Complete Simon's storyline
Dracula - Complete True Story Mode with Dracula
Death - Complete True Story Mode with Death

Unlock the following difficulties by completing the game on the corresponding difficulty:

DIFFICULTY LEVEL - HOW TO UNLOCK
Unlock Hard Difficulty - Complete Story Mode on Normal
Unlock Brutal Difficulty - Complete Story Mode on Hard

To unlock True Story mode which has a different background, two Aeon fights, and an extra final boss, and the Time Reaper, beat Story mode.

Unlock the following Character Stories by performing the corresponding tasks:

STORY - HOW TO UNLOCK
Aeon's Story - Complete Dracula's Story
Carmilla's Story - Complete Eric's Story
Cornell's Story - Complete Carmilla's Story
Death's and Shanoa's Story - Complete Trevor's Story
Dracula's Story - Complete Story Mode with Simon, Alucard, Maria, Eric, Carmilla, Grant, Golem, Sypha, Cornell, Trevor, Death, and Shanoa
Eric's Story - Complete Maria's Story
Golem - Complete Grant's Story
Grant - Complete Sypha's Story
Maria - Complete Alucard's Story
Shanoa's Story - Connect to DS with Castlevania: Order of Ecclesia cart
Sypha's Story - Complete Simon's Story
Trevor's Story - Complete Story Mode with Simon, Alucard, Maria, Eric, Carmilla, Grant, Golem, Sypha, and Cornell