The ball comes with four "seats", two are for the players one directly under the ball and one a distance away. Select the one under the ball to play keep-up, or put someone on both spots to volley it back and forth.
The remaining two places are "reset" spots, when you've finished playing stand on one of the reset spots to stop the animation.
If you want an even bigger beach ball check out "Humungous beach ball!!"
If you want a smaller beach ball (why?) check out "Small beach ball play"
