It's only been released in Japan for a reason.
The basic story is that a bunch of colossal monsters have awoken, which is a bit of a problem as millions of people have built cities on them. You're a member (theres a fair number of playable characters) of a group of warriors with the ability to turn into a dragon, so you race to the aid of the world and attempt to destroy the giant beasts.
Sounds good? That's what I thought. My japanese isn't great, but I understood enough to read all the menus and figure out mission objectives, although I can't offer much on the story. Pretty much, combat involves clicking on the screen with the stylus, double tapping for combos and that's about it. Your character has ranged attacks, so you just click on the behemoths weak points over and over to damage it.
The graphics are nice but combat is just too simple. You level up and gain experience, and there's a decent crafting system, but combat is just clicking over and over. It's possible to dodge attacks by pressing L, but the boring combat will drive you insane pretty quickly. You can't even choose to use the face buttons, you just have to click.
It's pretty crummy. Don't think you're missing out on a great Square Enix game, because you're not. Gamespot would give it a 5.5, tops.