Gravity Sandbox

Click anywhere on a dark canvas and a planet springs into existence. Set its size, density, and color before releasing it, then spawn another — and watch the two begin curving toward each other, trading orbits or smashing together in a shower of merged mass. Each body you add reshapes the gravitational landscape for everything else, so a system that looked stable can spiral into chaos the moment you drop in a dense interloper.

It's a quiet, tinkering kind of experience. There's no score, no timer, no failure state — just Newtonian physics doing its thing in real time. If you enjoy hands-on interactive simulations, this sits comfortably in that space. For something with a similar pull, Black Hole Simulator focuses that same orbital mechanics concept through a single dramatic object.

Works best with a mouse on desktop, where precise clicks let you place bodies exactly where you want them — touch works too, but a crowded system gets fiddly on a small screen.