Grandia Extreme

In-game reset:
Hold L1 + L2 + R1 + R2 and press Start + Select during game play.
Charlie the man.

Bonus adventure:
Successfully complete the game and save when prompted. Reload the saved game to access a new dungeon with 100 floors.
wsmith99.

Hint: Extra Bosses:
After gaining 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.
Chris.

Hint: Mana Eggs:
When you arrive at the second Geo Gate in the Aqua Ruins, take it to Locca. When you arrive there, take it back to Tsunami Trough - Ocean Cave. When you arrive there, go to your right and walk all the way to the end. There should be a huge oyster here. Cut it open by pressing Circle when you are next to it. It always contains expensive items you can either sell or use, and Mana eggs are almost always found here. The Aqua Egg is found more often, but the occasional Wind Egg or Stone Egg will also appear.
Anthony Portz.

Use the following trick to get a Mana Egg in under two minutes. Upon reaching Light Ruins late in the game, go through until Light Ruins level 2. Enter the Chasm level 2, then back out into Light Ruins level 2 again. Walk in a straight line (avoid the first elevator, where you came from) all the way to the other end to board the elevator up to a secret chamber, where a Mana Egg is sure to appear. Go back to entrance of Chasm to reset the Mana Egg generation. The entire back and forth trip takes just under one and a half minutes. Repeat this as desired.
ken.

Hint: Producing powerful Mana Eggs:
If you mix 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.
Bader Al-Jahwary.

Hint: Mana Egg symbols:
When junctioning Mana Eggs, small letters may appear. Some of their meanings are as follows:
MarloCKingJr and Anthony.

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.

Hint: Easy experience:
Try to kill Lucky Mink, a rabbit-like creature. It only has 18 to 20+ HP, but gives over 40,000 experience for each character when killed. It first appears at Starry Corridor level 11 to 14. The Creature is fast, difficult to kill, and will try to escape most of the time. If you want to face it, you need to carry the skill "Coercion" (three of them), and use Mana Eggs that have many hit abilities, such as Zap All, Diamond Dust, Galactic Bang, etc.
Ben Tsao.

Hint: Combo killing machine:
Titto attacks three times with his knife when you use his combo attack. You can use this to your advantage. First, give him all the best strength abilities and armor; and always give him the best weapon. Whenever you add more strength, raise it to the max. Always have a few strength abilities and whatever ability for the area you are in, such as Grappler for Humanoid creatures, for extra damage. If you can get the Golden Armor from the skill shop, do so and give it to Titto. Always have him in your party and keep him as high as you can. After you have completed a dungeon such as Flame Ruins, return when the monsters are more difficult. If you have the correct abilities equipped, Titto should be able to kill each one in about one to three combo attacks. If possible, give him lots of powerful Mana Eggs. In time you will have an extremely powerful asset to your party.
MattBMXr.

Glitch: Mystery legs:
Immediately when you start playing In the first Barrack, go in one of the rooms on the second floor with a table. There are a pair of legs under the table, even though there is no one there.
Edvin.