Finished it. I dunno, I think a lot of people felt the same way as you, lyte. The game LOOKS so good, and the screenshots were so amazing-looking, it was very easy to get hyped. But the problem is there's very little underneath.
Once you finish the game with all five characters, a new book opens up which has the final battle. The sad thing is that the final battle has five bosses, and it still recycles two of them from the main story. :/
I will give the game props for one thing, and that's (spoiler related to the ending ahead, don't think anyone cares)
spoiler (click to show/hide)
having the cojones to kill off the entire world in the armageddon instead of finding some bullshit solution to avert things at the last minute. They even kill off the cutesy fairy princess.