From the trailer, it appears to be a call-and-response type of system: the game shows a motion or button press right before you're to attack, and then a successfully on-beat press of the correct button connects. It's somewhere between Simon and a Quick Timer Event, or something.
Between the rhythm-battle system, the communication elements between players, the dinosaur-raising, and the animal-riding, there seems to be a lot going on in Jawa -- much more than the simplistic style suggests.
[Via NeoGAF]
