Dark:
Successfully complete the game in story mode to unlock
Dark as a playable character.
Variel:
Defeat Variel during game play in story mode to unlock
her as a playable character.
Easy weapon points:
Set the difficulty to easy and play the game in story
mode. Save the game just before ending a level and
change the difficulty to hard. Complete the level to get
the weapon points for the hard difficulty setting.
Change the difficulty back to easy when starting the
next level.