Easy character unlocking:
Play an Xbox Live multi-player game and complete a stage using an unlockable character that other players in your group do not have or vice versa. After completing the stage, the players that do not have that character will now have that person unlocked.
Easy Mode:
Lose the game three times on purpose and then choose to continue.
Unlock Characters and Stages:
Tenshin: Beat stage two in story mode.
Linda: Beat stage one in story mode.
Michael: Successfully complete the game in story mode.
Void: Complete Stage 4 in Story Mode
Kaede: Beat Stage 6 in Story Mode
Spike Sr: Beat Stage 7 in Story Mode
White: Beat Stage 5 in Story Mode
Hong Long: Successfully complete stage 3 in story mode
Astro Mall A: Beat Stage 7 in Story Mode
Astro Mall B: Beat Stage 7 in Story Mode
Ship Yard A: Beat Stage 4 in Story Mode
Ship Yard B: Beat Stage 4 in Story Mode
Imperial Opera stage: Successfully complete the game in story mode
Diesel Town in Battle Street mode: Complete Stage 3 in story mode
Spiker's Camp in Battle Street mode: Beat the level in the story mode