We’ve seen plenty of Final Fantasy XIII movies. These are actually from the game. To be more specific, the demo that shipped with Final Fantasy VII: Advent Children. Thanks to an early leak you can see how the game looks and the combat system without importing it.
Two immediate observations: random fights are out and the customizable three hit combo system makes watching fights more exciting compared to seeing the same sword slashing animation over and over. I didn’t want to spoil the demo too much since a copy is heading my way whenever Play-Asia ships it.