Grandia Extreme Cheats

In-game reset:
Press and hold L1 + L2 + R1 + R2 and push Start + Select while playing the game.

Bonus adventure:
Finish the game and save when prompted. Reload the saved game to access a new dungeon with 100 floors.
User Cheat by LimitedLaughter

Getting extra Bosses:
Upon receiving access to the Starlight Park, return to the various ruins and proceed to the end of each. You will find a Boss or group of Bosses to defeat. It is recommended that you be at level 30 or higher.

Producing powerful Mana Eggs:
By mixing a powered up Stone Egg and a powered up Fire Egg you will get a powered up Lava Egg. First, get all of your Fire Eggs and mix them together. Then mix, all your Stone Eggs together. Finally mix the two eggs and you will end up with a wonderful Lava Egg. You can also do this to other types of Mana Eggs.

Mana Egg symbols:
While junctioning Mana Eggs, small letters may become visible. Some of their meanings are below:
 

R: Adds to range of spells.
MP: The MP cost of the spell decreases.
P: The strength of the spell itself increases.
H: Spells with multiple hits will hit additional times.
W: Spells with an area/fan/around effect will have a wider range.
S: The time it takes to charge the spell will decrease.
IP: The spell will deal more IP damage.