Algodoo

There are 4 balls

All three of them change the color of the blue ring based on how far they are from their destination.

One ball follows anything red.

One ball's destination is controlled by A and D.

One ball is mousecontrolled.

One ball goes to a certain x coordinate that you specify by putting a number in the controlleracc of the blue ring.

Each ball is completely the same except for about one line of coding.

have Phun