Scroll Add or remove particles. Mass is perfectly conserved otherwise.
Collapse & Growth 5 particles of the same color gathering tightly collapse into a Black Hole. Black Holes absorb their own kind to grow and violently repel the opposite color. If a hole starves, it melts back into particles.
Collisions Identical Black Holes merge. Opposite ones annihilate in a massive Big Bang.
Overgrowth If a Black Hole grows large enough to touch itself across the Toroidal space boundaries, it triggers an instant collapse.
Toroidal Space Particles crossing the screen edge teleport to the other side and invert their color.