260 small bodies orbit a star and pull on each other. Bodies that touch merge, conserving mass and momentum.
Tap to drop a ring of debris. The same ?seed= always gives the same run.
LITPlanetesimal accretion (Safronov; Wetherill). Mass must be conserved exactly (the star and escapes are tracked), or the page throws.
AMBER2D and with exaggerated sizes.