Playground uses a tetherball to control video. The tetherball is impregnated with an accelerometer that detects movement and impact. A video feed of a couple kissing is linked to the tetherball. When the ball is not moving, the video feed plays slowly frame by frame. As participants play with the tetherball, their energy is transferred to the video and can be seen as the video speeds up. As the ball is hit hard, the video feed will change playback directions each time the ball suffers an impact. When the ball stops moving the video slows down again.