There's no doubt that Final Fantasy XIII is the most drastic departure yet from the series' template. Square Enix have stripped this game down to plot, visuals and the battle system, excising exploration, sidequests and, to a degree, complexity. Though this change will appeal to some and repel others, Final Fantasy XIII is a first class game. The production values are simply stunning and the battle system is one of the series' best.
It's certainly not without flaws; pacing, the party limitations and the levelling system taint the experience. There's also the reduced capacity for exploration and sidequests. But in the end, Square Enix set out to deliver a focused, cinematic, story-driven video game, and Final Fantasy XIII will give you just that.