I know it's been said 1000 times before and I know that many have said it better than me, but this game SUCKS.
Okay okay. I have reasons for this. I'm not just blindly hating the game. In fact, I completed this game 100% (got the platinum trophy twice). For a game itself it's not the worst thing I've ever played, but for a Final Fantasy game it's a disgrace.
First of all I suggest you watch The Spoony Experiment's review on FFXIII (it's on youtube and on his website) He has a lot of the same complaints I do about the game. He is also very funny and interesting. With that said, I absolutely HATE the story in this game. It makes little to no sense. Half of it is just random concepts that were pulled straight out of the writers ass such as nonsensical terms like l'cie, pulse l'cie, and fal'cie. The other half is a bunch of whining between the characters.
It's common knowledge that Final Fantasy always had stories that were convoluted and stupid like this, but it was NEVER this bad. To sum it up, there are six characters. They all get cursed with this evil power that makes them somewhat stronger. The tradeoff is they have to fulfill their focus in the allotted time or else they turn into zombies. The problem with this is they don't know what their focus is because they are never told by the fal'cie or demi-gods what that focus may be. Why? Well fuck you, that's why.
Seriously. They give you the lamest excuse why they can't tell you. Something about the fal'cie being far too complex for the human mind to understand. WTF? To make it worse about halfway through the game we meet a fal'cie that can speak to humans perfectly fine. So the fal'cie send you on this important mission that they want done or else they will make you into a zombie, but they won't tell you what that mission is. However, they are perfectly capable of just opening their mouth and explaining it to you. Oh and you know what the reward for fulfilling your focus is? Being turned into a crystal. Geez a shot to the head sounds like a better way to go.
I know I'm missing a lot of detail here, but I'm not going to spoil it in case you actually want to play this load of horsecrap.
What most people complained about is the combat. "It's all auto battle.", "It's too easy.", and "You can play it by mashing the X buttom.". And you know what? They are all true claims.
The combat is painfully boring. Okay to be fair, you kind of have to try by changing your paradigms which is like your characters class or role. You get six basic roles.
Commando - Physical Attack, used to slow down the stagger bar from falling and doing damage once staggered.
Ravager - Mage like role where you build up the stagger bar so that you can do more damage to a monster.
Sentinel - Defender. Does nothing aside from soaking damage.
Medic - Standard RPG healer.
Synergist - Buffs the party with beneficial spells.
Saboteur - Debuffs enemy party with negative effects.
You can mix and match your party compositions. Like if you want to have some Defense and attack you can go SEN/COM/RAV or COM/MED/RAV. Or if you want to buff up and heal you could go SYN/MED/SYN or SYN/MED/MED. Making combinations was a little fun. I'll grant you that.
You also get some special moves that can't be used with auto-battle and you'll have to manually select such as Lightning's Army of One or summons, but it's really all the same crap.
In the end you're not the one fighting the battle. Your characters are. You just sit there and watch as they slowly take out the enemy's HP. It's boring, but it can be occasionally flashy to watch. Some actually claim it's hard. This is entirely false. Nothing about this game is challenging. If you want a challenge go play anything before XIII.
The other major complaint about the game is that it's linear. After playing the game for over 200 hours (on two separate play-throughs)I can say this is partially true. The game is pretty much one big hallway, but towards the last few chapters there is a lot to do on the side world. And if you are a fan of grinding games like me, then you'll probably have fun with all the marked missions, although that's about as far as the exploration and depth goes. This is no Kingdom Hearts, nor FFX, nor is it on par with many JRPGs content.
The graphics are (or should I say 'were' giving that this is now a four year old game) pretty good, but nothing you haven't seen before. Graphics don't make the game and they sure as hell don't make a bad one any better.
The music is OK, but honestly Final Fantasy I-X (not counting the MMOs) had much better music thanks to Nobuo Uematsu because he's pretty much a Japanese Mozart.
But what really, and I mean REALLY makes me mad about all this is the fact that they made a franchise out of this! I could forgive Square for making a mistake, but DON'T keep making the same mistake over and over again. Final Fantasy XIII-2 and Lighting returns FFS. I heard a rumor that they might even make another game in the XIII world. Please no! I beg you Square! Make a new game! Move on! You made a mistake, now move on. Don't try to justify it by making more crappy games about it.
Well with my personal opinions aside. Final Fantasy XIII and all of it's two sequels sold well worldwide. Sad really.