Flappy Koi.

Tap, click or press space to kick upward. Every pillar pair is a point, every fifth point sets off a gold flash and confetti, and medals land at 4, 8, 15 and 25. Your best score stays on your device.

Speed climbs 2.5 percent with every point, the gap narrows from about a third of the screen to a quarter, and from the third pillar on the gaps start drifting up and down. Simple rules, and a ramp that keeps you one more try away.

It started as a plain yellow bird, built in a few hours to prove the feel. Version two swapped in a painted set: a koi with a two-frame swim, torii posts and a pond, generated as one matching family and cut out frame by frame. It looked good as a set, but the koi never quite worked at game size, so version three went back to code: the koi, the water and the pillars are all drawn live. Lighter, sharp on every screen, and the version that shipped.

Safe-area aware on notched phones, no accidental double-tap zoom, sound made in the browser instead of downloaded, and nothing to install. The whole game weighs less than most hero images.

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