TUNDRA

TUNDRA is a bush-plane STOL competition, the way they actually fly it in Alaska: golden hour on a glacial gravel bar, a fabric-and-tube taildragger on fat tundra tires, and a scoreboard measured in feet, not seconds. Three rounds. Each one scores your takeoff (brake release to wheels-up) plus your landing (chalk line to full stop). Lowest total beats the rivals. Touch a wheel down even a foot before the line and the round is scratched — flat 400 ft penalty, no argument from the judges.

How to play

• W/S elevator · A/D ailerons · Q/E rudder · X/Z throttle · F flaps down, G up · Space brakes · Enter releases the brakes · C cycles chase / cockpit / judge cams. Arrows mirror WASD, there's a pitch-flip toggle, and full touch controls on mobile.
• Takeoff: full flap, stick hard back, full power against the brakes — then wait.
• Fly the little pattern past the turn point, then come back and put it down just past the line at walking pace, brakes on, stick back (stand on the brakes with the stick loose and the tail comes up over the prop).

The twist

The valley wind is a living thing — a real gust cycle streaming down the river, averaging 8 knots, gusting to 20, dying to 2, wandering fifteen degrees either side. The windsock, the grass, and the ripples on the water are telling you the truth about it, and every foot of headwind is free runway. Real STOL pilots sit at the line and wait for the gust. So will you. The wind you take off in is the same system you have to land in ninety seconds later.

Under the hood it's a genuine flight simulation at a fixed 1/120 s step — quaternion rigid body, a lift curve with an honest stall break (42 mph clean, 33 with full flap), prop slipstream over the wing and tail so you can hang it on the prop at 30 mph behind the power curve, ground effect that floats a fast flare, sprung taildragger gear with the mains ahead of the CG so a ham-fisted brake application noses you over because the moment arithmetic says so. Nothing is scripted: the greasers, the bounces, and the nose-overs all fall out of the same equations.

There's a leaderboard (total feet across three rounds — lower is better) and six badges to earn, one of them hidden.

Made in one run by Claude: the concept, the copy and the review by Fable, the aircraft and its physics built end-to-end by an Opus agent, playtested and tuned headlessly against its own simulation before shipping. One HTML file, three.js vendored in-repo, every sound synthesized in WebAudio.