Final Fantasy XIII isn't too great of a game. I probably would not dislike it so much, however, if it wasn't a prime example of wasted potential.
That basically summarizes the game's battle system: wasted potential. On paper, the battle system sounds like the best the series has had yet. A perfect blend of the strategic elements of class Final Fantasy titles and the fast-paced action of other games. And during the first few hours, you really would think that the battle system is the best in the series. So how could it go so wrong? Well, there's a couple of problems with it. First and foremost, the combat becomes repetitive. While one may think the game allows for a ton of strategic depth, the way most of the enemies are structured and the way most of the abilities are designed ruins all of its potential. Bosses will become spamfests, determined by how quickly you can change paradigms and hope for the best. Secondly, not being able to control individual party members is a real detriment. while it may work in a game like Mass Effect, 2 where the level design matters as much as the enemies you are fighting, for a game like Final Fantasy XIII, in which the outcome of a battle depends purely on your combat choices, it only hinders the experience.
As for what was mentioned in the beginning of this review, that also summarizes the story: wasted potential. The underlying lore, setting, and atmosphere of the game, in theory, compose great fodder for a story to be told. However, unfortunately, the execution of the story-telling is just plain terrible. Many of the character sound like broken record players; repeating the same spiel over, and over, and over again. The most notable offenders are Hope (Mr. "I don't think I'm strong enough/I'm gonna KILL that Snow") and Snow (Mr. "We're the heroes! Never give up!"). The rest of the crew, Vanille, Lightning, and Fang, are incredibly one-dimensional with no real depth; the only character with any real depth and memorable personality traits is Sazh. And it says alot about a game if the most memorable character is a middle-aged man with a baby bird living in his 'fro.
Finally, the music isn't that great, either. While some of it is good, such as the battle themes, alot of it devolves in to cheesy J-Pop. *crag*, the worst offender is the chocobo theme; they gave it *crag*ing lyrics. You don't give lyrics to the chocobo theme. You just plain don't.
So yeah, ultimately, I'd call this game more "disappointing" than "bad." If you're a die-hard fan of the series, you should probably get it, but be wary. If you're not a member of the FF fanbase, well, this game definitely isn't going to convert you.