If you have five spare minutes, Bubble Glide will fill them. Everything happens on one screen with gaps that start at 50% of the screen and shrink with every point, and the whole thing runs straight in the browser - no downloads, no sign-ups, no fuss.
Scoring is per pipe, and the difficulty comes from variety - gap heights drift up and down the screen, so no two pipes arrive the same way. The ramp is honest: nothing suddenly teleports, the world just stops forgiving lazy taps.
It suits anyone with a queue to wait in or a kettle to watch: students between classes, commuters, parents stealing ten quiet minutes. There is no meta-progression to lose and nothing to catch up on - a week away costs you nothing but a little sharpness.