I don't know why everyone hates on XIII.....it has nearly the same linearity of X, except you cannot revisit past cocoon locations. Thats it. Oh and maybe a minigame here or there with monster catching, chocobos, and hidden airship locations. But really, the extra sidequests with titan's trial, the final trial guy (even though he was a pussy tbh), and all the trials which are optional....i don't know.
FFXIII to me, was a very very well made game. If you look past the linearity and take it for what it should be taken for (an "Experience), you'll most likely love it just like i do. I'd like to see the lore they created explored in 2 as the others above me said. They have very little to do to the engine running the game most likely, and these next months until november (or whenever they're planning for japan release), will probably be all script/story and gameplay. I'm probably one of the few that wont care if the gameplay is near the same....it was fun.