Unlock Sixth Class:
     At  the  Class  Selection screen, highlight the classes and press
the  R  Trigger  in  this order - Pirate, R Trigger, Thief, R Trigger,
Warrior,  Trigger  R, Archer, R Trigger, Pirate, R Trigger, Warlock, R
Trigger,  Thief,  R Trigger, Warlock, R Trigger, and Thief, R Trigger.
This must be done quickly in order for it to work.

New Character Class:
     Press  R  as  you  highlight  a  character in the Class selection
screen to unlock a new character class.