Algodoo

Originally tried to have an orbit capture, and this turned out to be fun. Select a random circle and follow it.
Note 1 - Circles which collide with the star will evaporate and their ghost tracer will be shooten into the last trajectory it went.
Note 2 - Circles can collide, if they, again, will evaporate and their ghost tracer will be shooten into the last trajectory it went.

P.S. there is a unstable planet and a star far away from this cluster.

SMASH THAT PLAY BUTTON! You see the simulation in 100x speed.