They made it a LOT less linear. The story is enjoyably stupid (rather than facepalmingly stupid like FFX-2), there're lots of worlds to explore, there are towns, the battles are quicker, the level-up system is better, the characters aren't annoying. That's all I can think of off the top of my head.
--
James - Board 8's Resident Warm And Safe, Slipper-Wearing User
& The Cream of Porcupine Tree Fanboyism