Play a one-button flying game: tap to flap a dragonfly up through the gaps between hanging rocks and reed beds, with a calm level for the youngest players.
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Tap the pond, press the Flap button, or press Space, the Up arrow or W to flap. The dragonfly flies by itself and sinks when you stop. Escape or P pauses. The game waits for your first flap. Calm is for the youngest players: wide gaps, slow flying, and a bump just puts the dragonfly back in the gap and carries on.
Sixty times a second the game adds gravity to the dragonfly's speed and moves it. A flap does not add up: it sets the upward speed to a fixed value, so tapping faster does not make a bigger jump. Each new gap is placed no further up or down than the flight physics can comfortably cover in the time between two columns, so every gap can be reached. You score a point as you fly past each column. Touching a rock, a reed or the water ends the run, except in Calm.
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A dragonfly flies across a pond by itself. You keep it in the air. Tap or click the pond, press the big Flap button, or press Space, the Up arrow or W to beat its wings and rise. When you stop, it sinks. Fly through the gap between the hanging rocks above and the reed beds below. You score one point for every column you get past.
The game waits for your first flap, so there is no rush to start.
| Level | Scroll speed | Gravity | Gap | Distance between columns |
|---|---|---|---|---|
| Calm (little ones) | 78 | 560 | 150 | 270 |
| Easy | 95 | 760 | 124 | 250 |
| Medium | 115 | 1000 | 106 | 232 |
| Hard | 135 | 1150 | 92 | 215 |
All numbers are in the game’s own units: the world is 400 wide and 300 tall, speed and gravity are per second. The harder the level, the faster the world moves, the stronger gravity pulls, and the narrower and closer the gaps.
Calm is for very young children. The gaps are wide, the flying is slow, and nothing ends the run. If the dragonfly bumps a rock or reed it is set back in the middle of that gap and gets one and a half seconds of safety. If it touches the water it bounces gently.
Rocks and reeds look different from each other, and you never need the colour to tell them apart: rocks hang from the top in lumpy stacks, reeds stand up from the water with cattail heads.
Score changes are written into the canvas label, and a message line says what happened when a run ends and at every ten gaps. When you ask your device for reduced motion, the world scrolls 20 percent slower, and the hills, ripples and wing flutter stop moving. Nothing flashes. There is no screen shake. There is no sound.
The engine is a pure function: step(state, flap, rng) advances the game by exactly one 1/60 second and returns a new state. The page runs it from a fixed-step clock, so a 60 Hz phone and a 144 Hz monitor fly the same course, and a stalled tab cannot fast-forward it (one frame is cut off at 50 ms).
Why every gap can be reached. The tests work out, using the same integrator the game uses, the best height a flapping rhythm can climb and the distance a free fall covers in the time between two columns. The biggest allowed jump between gap centres, plus the room inside a gap, times 1.5 must still fit in both. That holds for every level, also at the slower reduced-motion pace.
That is a bound, not a play-through, so the suite also flies it. A simple simulated pilot that knows only where the middle of the next gap is, and nothing about how the generator works, flies 120 gaps on 25 different seeds on every level, at normal and slower pace, without ever bumping a rock, a reed or the water. A pilot that ignores the gaps and just hovers does not get far, so the check can fail.
A seed replays exactly: the same random numbers and the same flaps give the same flight, and a different seed gives a different course. The page takes its random numbers from the browser’s secure random source.
Nothing is uploaded and there is no account. Your best number of gaps for each level (and for the slower pace used with reduced motion) is saved in your browser’s local storage under one key, as small whole numbers inside a small JSON object. The page address holds your level so you can share it. Clearing site data removes the scores.
For informational purposes only. Not financial, medical, or legal advice. You are solely responsible for how you use these tools.