Quirky is Beautiful
That aside, it's a beautiful game, one of the best isometric turn-based strategy games in existence. Playing as demons? Awesome - playing as demons who can stack on top of each other for "throw me around the battlefield" fun? Truly awe inspiring.
The main storyline should give you a good amount of gameplay, though completing all of the secret endings will easily consume 300+ hours of your life. You won't regret spending this much time with the game though, the anime "next time on Sailor Moon" style cut scenes, the quirky characters, the hidden endings, the great dialogue, and the very fact that you can go to war against Heaven itself will keep you entertained for hours on end.
It's rare to see a game like this make it to the states, the stance has been taken by companies that games that could offend the religious audiences should not be brought to America, so get your hands on this gem while you still can.