When you have gone through the game and the ending sequences have completed you will be able to go back and access places in the world without having to battle enemies. Go to the first forest dungeon where you originally met Reala (Lens girl) and a FMV sequence will play. When it has completed you will be asked if you want to 'Save', save your data on another slot and then go to the 'Loading' screen and load it. When it has finished loading you will be at a shop where you can trade in your Grade Points that you earned for extra features like Stats, Extra Items, Double Experience etc. There is also a hidden dungeon which can be accessed by collecting the '15 Unlucky Stones' that now exist in the world.

Extra Dungeon
Complete the game and save it. Then load it back up and you can play an extra dungeon.

New Game+
This feature allows you to alter the options after you have completed the game. To activate this complete the game and savem as described above, but this time when you load the game back up press triangle and this will create New Game+

Evil Mode
This new difficulty level is unlocked after you have completed the game once.

Chaos Mode
This new difficulty level is unlocked after you have completed the game twice.