Completion bonuses
Successfully complete the game and save it when prompted. Load the cleared saved game file by pressing Triangle to start the game with new options. You may also load the cleared game file normally to resume the game at the room prior to the final Boss. There will now be a clown NPC in the room. Talk to him, then return to where Rutee was first encountered to find the clown again. Talk to him and select the first option to enter a bonus dungeon. Each floor completed will give you EX points that are used to buy items from the clown, via his third dialogue option.
Unlockable - How to Unlock
Chaos mode - Successfully complete the game twice
Evil mode - Successfully complete the game
Coliseum bug: Permanently max out Swordian Device Points
Go to the coliseum in Noischtat and select Definite Mode. Take Lion, then fight against the Cave Head on Hard or above. If you perform a Definite Strike against it (Garyuusen-> Garyuu Meppa-> Kuushuuken), your entire party will gain Swordian Device Points, even though you are never supposed to receive any at all. It's a programming error, and it allows you to keep performing Definite Strikes to permanently max out your SD Points at 999 very early, no matter how low your characters' levels are! (Note: Hard mode yields 3 points, Evil mode yields 4, and Chaos mode yields 9).