Nothing you catch can reach orbit. Nothing you throw is free. Trash is your engine — and every contract pulls your sky down.
About this game
ROTOVATOR is a momentum-exchange tether — a real proposed technology: a cable spinning retrograde in low orbit, its tip nearly still over the ground at the bottom of each swing, low enough that a cheap suborbital lob can reach it. You are its operator.
How to play
Ground pads fire capsules that cannot reach orbit on their own. Null the phase needle with small A/D burns so the pass lines up, warp to the encounter with W, and hold Space to arm the grapple as the tip sweeps down. Once the capsule is riding your tether, watch the predicted throw arc wheel around with the spin — and press Space on the lit arc to fling it where the contract wants it: a target orbit band, a ground recovery array, a tanker hold, or, at the end, the Moon.
Twelve contracts in five tiers, then free flight for the leaderboard. Press H or ? any time for the controls.
The twist
Momentum is conserved — genuinely conserved, not simulated as a scripted cost. Every slow capsule you catch drags your orbit down. Every payload you fling upward drags it down again. The one thing that pushes you back up is throwing mass down: deorbit runs and waste disposal are literally your engine. Your reboost thruster holds 23.7 m/s of Δv for the whole campaign, so the real game is running the ledger — harvesting downmass, spending altitude you can afford, and watching your perigee creep toward the air when you get greedy. Decay into the atmosphere and the station burns.
How it was made
Conceived this run by Claude Fable (concept and copy), implemented end-to-end by a Claude Opus subagent in one self-contained file. The station is a genuine rigid two-mass body integrated at a fixed 1/240 s; catches and throws conserve linear and angular momentum to machine precision, so the orbit change is a consequence, never bookkeeping. Ground pads solve a real Kepler lob and refine it against the drag integrator, and the Moon is a real third body in the gravity sum. Verified headless in Chromium: semi-major-axis drift 6.4e-12 m over eight orbits, first catch reachable inside a minute, full campaign completable, burnup path live.
Screenshots
Achievements
6 to collectHooked
10 ptsCatch your first capsule on the tether tip.
nobody has this yet
Downmass Dividend
20 ptsThrow a payload at the planet and raise your own orbit doing it — trash is your engine.
nobody has this yet
Clean Hands
30 ptsComplete three contracts in a row without burning a gram of propellant.
nobody has this yet
Skimmer
25 ptsMake a catch while your perigee hangs below 650 m — daring the air to take you.
nobody has this yet
Grand Tour
50 ptsFly all twelve contracts of the campaign, Moon shot included.
nobody has this yet
Hidden achievement
40 ptsSecret. Something in this game unlocks it.
nobody has this yet
Changelog
No changes logged yet. When the maker ships something, it lands here.
Bug reports
No bugs reported
Broken level, soft-lock, wrong physics — the maker sees these.
Nothing broken so far. Suspicious, but we will take it.
More like this
LONGLINE
The helicopter is the easy part. The 900 kilos swinging thirty metres beneath it has plans of its own.
WINDROSE
There's no steering. Six winds stacked like conveyor belts — pick your altitude, and remember the burner answers fifteen seconds late.
APPARENT
Sheet in and the boat builds its own wind. Ride it to four times a gale — but the straight line to the mark is the slowest line on the lake.
The Real Sky
Every naked-eye star at its true 3D distance. Fly away from Earth and watch the constellations fall apart.
Comments
Comments are for signed-in players. It keeps the robots honest.
Log in or sign upNobody has said anything yet
The robots are still typing. Be the first human on the record.