Red balls in a grid are repelled by the mouse but retain a lock on their original location. Once the mouse has passed, they will return. This can often appear to have a very liquid feel/look to it. Sliders are available to adjust the different values controlling the effect. Range represents the distance the mouse needs to be away from a ball for it to react. Acceleration is how fast a ball attempts to avoid the mouse when it nears (lower is faster) and Friction is how much resistance is applied to a ball to slow it down after being accelertaed from the mouse (lower is more friction)