Since the game is being played with "up" "down" and "aggression" buttons, I'm worried it'll get stale in a hurry. The trailers have both looked nice, though.

@wanion: There aren't mandatory rules; the guy playing doesn't know you can roll to negate fall damage.

@Cheroro: It's optional. I think you have to press a button or stand still. You can even disable it entirely.

Oh, and when you pick up guns, you lose mobility. They are deliberately trying not to make a standard FPS.