Single player map select
Select strategy mode, then highlight the "Set War" option. Press Circle + Square. Then, press Select(4), Start(3), Square(2), Circle, Circle + Square. Any single player map may be selected for game play.
Secret Warriors and Mayhem Backgrounds
To release two secret fighting backgrounds, beat Strategy Mode on Normal level with each side. The Arcane victory will release the Menhir Circle; the Teknos, the Dark Maze.
To gain control of two secret super-warriors, beat Strategy Mode on Hard level. The Arcanes earn the nasty MegaPrana, while the Teknos recieve the Beta-Razorfane, their first truly effective flying character.
All of the above are usable in Mayhem Mode only.
Easy extra characters
To make this code work, you first must go to mayhem mode, highlight the Set Teams options, then hold L1 and press square + circle. Then press: Select(4 times) Start(3 times) Square(2times) Circle(once) and then press square + circle again. You will know if you got it right if all characters appear in the bottom right corner.