Simon Echo is a browser game built for short, satisfying sessions - it loads instantly, plays with one thumb, and runs on any mid-range phone. The setup is simple: patterns that speed up every level, down to 260 ms per flash. Nothing to install, no account, no waiting.
Each level adds one step to the light pattern, and the playback gets faster as the level climbs. You watch, you repeat, and one wrong tap ends the run. The patterns that speed up every level, down to 260 ms per flash, so late rounds feel less like a memory game and more like a reflex test.
Nothing here needs a tutorial or a wiki. Controls are one gesture, the goal is one sentence, and the difficulty comes from execution rather than homework. That is exactly what a browser game should be.