You can do everything Ash said, plus decide what characters to place in your party and fight these enemies that look like Reno's Pyramid effect and give off massive amounts of experience, basically allowing you to level up rapidly before jumping into a point in the game.

I'm sure there are other things to do, like play music and such, but I've only tried it once, since it's so prone to freezing up, and this is all I definitely remember.

The text in the menus obviously predates the final translation, as well, leaving you with phonetic names like Yufi and Ket Shi.