Hundreds of double pendulums, released a hair's width apart, swinging past a black hole.
Steer the black hole with your mouse or finger. It glides, it doesn't teleport, so read where the swarm is heading. Swallow pendulums in quick succession to build a combo. The gold one is worth ten. Missed a cluster? Rewind (or press R) to undo the last 3 seconds, but the clock doesn't go back with you.
Drag the slider to revisit any recorded moment, then press Play to branch a new timeline from there. Or reverse every velocity and see whether the swarm can fall back to where it started.
With time dilation on, a bob falling in appears to slow, redden and freeze at the edge, which is what a distant observer would see. Turn it off and bobs simply plunge through.
On a log scale, chaos shows up as a straight climb. Its slope is the Lyapunov exponent: how fast tiny differences grow. A black hole nearby makes the climb steeper.