Phase — free browser game

Phase is an observation-and-timing arcade built around catching the moment two independent sine waves cross. A dashed vertical 'capture line' sits in the middle of the canvas, and blue and orange waves continuously sweep across with different amplitudes, periods and scroll speeds. Each wave's instantaneous Y value at the capture line is marked with a dot in its colour, with a thin connector drawn between them so you can read the gap at a glance. Press Space — or tap the canvas — to capture the moment: the closer the two dots are, the more points you score. Within 6 pixels you get the full 100 points (perfect); the score falls off quadratically with distance and reaches zero beyond a 90 pixel gap. After every capture both waves are completely re-randomised with new amplitudes, periods, speeds and directions, so muscle memory doesn't help — you have to re-read the screen every time. Three perfect captures in a row pay a +25 combo bonus; a single 'miss' resets your streak, so trigger-happy captures are expensive. The round lasts 45 seconds; when time runs out the total is recorded and your best is kept in your browser. Strategy: don't try to predict the centreline crossing — the gap shrinks to zero whenever both dots travel in the same direction, and the firing window is widest just as they decelerate toward each other, not while they accelerate. Difficulty steps up every three captures, with speeds nearly doubling at higher tiers; chasing perfects becomes much harder, and racking up steady 'good' captures usually beats greedy perfect-hunting on overall score.