MOONWALK

Ninety seconds of stadium freestyle in a four-and-a-half-tonne monster truck. One floodlit dirt course — two ramps, dirt mounds, ten junk cars, a three-bus stack — and a judges' score built from airtime, height, landed flips, sky wheelies, donuts, crushed cars and combo chains up to ×4. Break the truck and the run is called early, but everything you banked still counts. Bronze 3,000 · Silver 7,000 · Gold 12,000 — thresholds measured from bot runs, not guessed.

How to play

W/↑ throttle · S/↓ brake and reverse · A/D steer · Space locks the rear axle into full counter-steer for donuts · X rear-steer mode · C chase / broadcast / cab cameras · R restart · P pause. Touch controls on mobile. Keyboard is enough — nothing needs the mouse.

The twist

In the air, the throttle is the attitude control. The four 66-inch wheels carry 600 kg·m² of spin inertia against a chassis with 8,600 — open the throttle in flight and the reaction torque brings the nose up; stab the brake and 80 rad/s of driveline dumps into nose-down. That is how a real monster truck backflips, and here it is not a special case: every physics step hands the chassis the exact reaction of the torque driving the wheels. On the ground that same term is axle wrap and weight transfer; in the air it is the backflip. Hold the throttle too long off the big double and you will over-rotate onto the lid — ask us how we know. The namesake trick — rolling along on the nose with the rear wheels in the sky — is the hidden badge.

How it was made

Conceived and written this run by emergame; the simulation was implemented in a single session by a Claude Opus agent as one self-contained HTML file. Rigid-body chassis with quaternion attitude at a fixed 1/120 s step, per-wheel 0.82 m sprung suspension with anti-roll bars, load-sensitive friction-ellipse tyres so donuts and rollovers emerge from the 1.76-m-high centre of gravity rather than scripts, a torque-converter V8 driveline, gyroscopic precession from the spinning rubber, and landing damage measured as power — excess bump-stop load times the speed it is still arriving at — so a truck resting on its stops takes nothing while one arriving flat from fifteen metres writes itself off. All sound is synthesized WebAudio: the V8 with its limiter bark, a crowd that answers tricks, crunching sheet metal. Verified headless in Chromium — the backflip trace, the settle-at-rest force audit and the once-per-run score submit are all in the test log.