HEADROOM

HEADROOM is a first-person FPV quadcopter race through a derelict power station at night. Three laps, fourteen gates: low across the cracked apron between transformer skeletons, through a pair of slot gates you have to roll to thread, up the flank of the cooling tower, over the rim — and then a helical descent inside the hyperboloid shell, out through a blown-out arch, and home through the dark turbine hall.

The twist

Thrust and steering come out of the same four motors, and each motor tops out at 100%. The flight controller mixes throttle, roll, pitch and yaw into four outputs the way a real racing quad's firmware does — and when you punch the throttle and yank the sticks at the same time, the mix runs out of room. Airmode gives your steering priority: collective throttle gets pulled down to protect the rotation you asked for, so the quad still turns, it just stops accelerating. Push further and the torque itself gets scaled back — yaw starves first, because yaw comes from prop drag and is ten times weaker than roll. The HUD's HEADROOM bar shows the room you have left; when it's red, the throttle you're asking for is being eaten by the steering. You can hear it too: the four motor voices are each pitched to their own RPM, and saturation tears the hover chord apart.

The fast line is the one where you know when to stop asking for both.

How to play

• W/S throttle (it's a position — it stays where you leave it), A/D yaw, arrows (or I/K/J/L) pitch and roll. Keyboard alone is enough.
• Mouse or gamepad for the cyclic if you prefer; two virtual sticks on touch.
• ANGLE mode self-levels and caps the lean — you'll be flying in ten seconds. ACRO is pure rate control, the real thing, and the only way to fly the fast line.
• Gates in order, wrong-way crossings don't count. Crash and you lose one of four airframes; lose them all and it's a DNF. Beat 3:40 to qualify; gold is 1:45.
• Watch for the propwash inside the tower — the shell traps your own downwash, and descending through it gets rough.

How it was made

Built this run by a Claude agent pipeline: the concept and copy from one model, the implementation delegated to another, verified in a headless browser before publishing. The mixer is implemented literally — mix range, torque scaling, airmode throttle fitting — not as a penalty curve. The medal times were set by strapping an autopilot to the same sticks, same PID, same mixer, and searching 300 tuning configs: the reference pilot finishes in 95.8 s and spends 26 of them with its throttle being eaten by the steering. Physics at a fixed 1/120 s step: quaternion attitude with the gyroscopic term, 22 ms motor spool lag, vortex-ring-state propwash, ground effect, and impulse collisions. Everything is synthesized — no audio files, no textures, no CDN.