After you're given access to the airship in Mycent, new weapons and armor will be made available for purchase in some of the town shops. After you beat the bosses in the four towers, even more new weapons and armor will become available to buy in some of the town shops.
Secret Battle
If you wander around on the World Map north of the Graveyard of Ages, you will stumble on a hidden set of ruins that looks like Karnait (the place where Pike was found.) There you find Olivia, Duke Lang's daughter, and fight the Iron Giant. After you kill it the second time, the Duke in Mycent gives you the Quest Pass. Use it in any store for a 20% discount.
Secret Scenario
After defeating the north tower, Kris will take Guy to Solace to be healed. Go to the sanctuary and when night comes go to the Gate of Solace. There you will meet Eka and Leos will give you some Miracle Mangoes. Now travel to Fargasta to meet your destiny.
Secret Scenario 2
After going to Gadel, go southeast. At the bottom of the continent, there is a cave with a girl in it. Talk to her, then return to Gigarl. There is an old man in Gigarl who will be interested of your findings. You will have to go back and forth between Gigarl and the cave. After a few messages, the old man will come with you to the cave and be turned young again. This scenario will provide you with nothing unless you haven't searched the pots.
Soundtrack
Play the disc on a standard audio CD player and listen to tracks 3 through 22 to hear the music from the game.
Unlock doors and chests
Press X + Y + A + B on controller two while in any location except the map or battle screens. All doors and chests will open and lights will extinguish.
New weapons and armor...