Well, it's up to you. If you play FFX-2 before you play FFX, you won't understand quite a bit of the story and should you go back and play FFX the ending will be spoiled for you. It is fun though. FFX is a good good but it is very serious and somber. They are two totally different games, but I would suggest playing FFX first so that you can see Yuna's character advance through the whole saga and not just the second game.