Launch a satellite into orbit around the sun. Too fast and it escapes; too slow and it crashes.
A sun sits at the center of the screen. A satellite waits beside it. Touch and drag anywhere to set the launch direction and speed — drag farther for more thrust. Release to launch.
Gravity does the rest. The satellite curves toward the sun continuously as it sails past. With the right speed and direction it loops back around and around.
A full orbit — the satellite sweeps all the way around the sun once — scores a point. The orbit can keep going and score more, until the satellite eventually crashes or escapes.
A launch fails if the satellite crashes into the sun or escapes off the edge of the screen. A failed launch costs you one of your three lives and a fresh satellite appears.
Goal: complete as many orbits as you can before you lose all three lives.
Faster isn't better. Too fast and your satellite flies past the sun and escapes the screen; too slow and gravity pulls it straight in. The sweet spot for a stable orbit is a specific speed for each launch distance, and you'll feel it after a few tries — the satellite that just barely curves enough to come back is the one that stays.
Aim perpendicular to the sun, not at it. A satellite launched directly at the sun crashes; one launched 90 degrees off the line from the sun is set up to circle it. The cleaner your perpendicular, the more circular your orbit becomes — and circular orbits last the longest.
Long thin orbits travel slowly at the far end. If your orbit is elongated, the satellite will appear almost frozen far from the sun, then whip around fast when it gets close. Counterintuitively, this isn't a problem — it'll complete the lap and score. Don't relaunch just because the satellite seems stalled at apoapsis.