I was so disappointed that I did not finish the game. I wanted to like it, and I even spent at least 12 hours playing the game trying to force myself to like it. But after a while, I just couldn't get myself to pick up the game anymore. I'm not saying this game is horrible, it's just that I'm very picky with games. I've probably only beaten 1/3 of the games I've started. For me, a game has to either have great gameplay or a great story to get me to play it. Both would be nice, but if a game has one of these i'll probably like it. IMO, FFXIII had neither.
Gameplay: (from what I played)
FFXIII doesn't really feel much like an RPG. It is completely linear and I always felt like I was doing missions or stages, rather than exploring places...especially because you could actually see the enemies and clear out a place. FFXIII doesn't allow the sort of freedom that makes an RPG an RPG. The whole time I felt like I was playing a game that was disguised as an RPG, but was actually an adventure game with a weird combat system. And so, since I could only look at it as an adventure game, the gameplay was pretty lame IMO.
STORY: (from what I played)
While the story isn't necessarily bad, it definitely is not good. I couldn't really understand it at first until I went online and read some back story. That should not be required...especially in an FFX game. And the characters were just plain annoying. I seriously did not like a single main character. I don't even know how that is possible when there are quite a few of them. I found it very strange when I actually found myself wanting to skip the cutscenes. For me, the cutscenes are a hugely important part in any RPG... i usually feel like i'm working my way just to see the next one. If the cutscenes weren't so pretty, I probably would have skipped some.
So yeah, that's basically why I did not like the game.