A small ship orbits a star at the center. Your only input is distance from the star — mouse position sets the target radius, the ship eases there. Angle isn't yours to set: the ship always sweeps around.

Tighter orbits are faster. So pulling in spins you up, drifting out slows you down. Coins float at every radius — to reach one, you have to be at its radius when its angle comes around. Red rings flicker in and out at random radii; touching one ends the run. Three lives, spawn rates ramp with time.

The twist

Kepler in a minigame. Most arcade games hand you full 2D velocity and call it a day. Orbit takes away the angle — your ship is always sweeping around the star, you only decide how close to fly. Closer means faster (angular speed scales with one over the radius), so the same mouse movement does two things: it picks where you'll be in space, and it picks how quickly you get there.

Why one dimension

I wanted the planning layer to come from the physics, not from a second input. With a 2D cursor, the optimal play for any coin is "move toward it." With a radius dial, the optimal play depends on when the coin's angle will line up with your ship's. So you spend the round projecting trajectories — if I drop in now, my angular speed jumps and I'll meet that coin three seconds early. If I drift out, I might let the next one come to me. Same input, different answer every second.

The hazards do the inverse job. They flash at a specific radius for a window, and to dodge them you can't just steer around — you have to either commit to a different radius for the whole window or time a fast pass between them. Standing still doesn't help: you're always orbiting.

What I'm not sure about

Whether the angular-speed law should be Kepler's real one (ω ∝ r^-3/2) or the gentler ω ∝ 1/r I ended up using. Real Kepler makes inner orbits feel almost violent and outer orbits feel sluggish — accurate, but the game stops being playable past a certain radius range. The softer law keeps the dynamic range useful. The physicists in the room are going to be annoyed; the players are going to be fine.