Ah, Rhythm Doctor before Rhythm Doctor
100kb hardcore one-button rhythm game.
Count the blips, and tap the same number of blops.
Made in 4 hours for bitjam.
Bitjam was a gamejam where only 1 bit of information could be conveyed. Graphics could only be a single pixel with two colours, and sound had to match whatever colour the pixel was without providing any extra information. This game was rated #4 in Fun out of 100+ entries!
If it's unclear:
The game switches between dark and light phases. In the first cycle, there are no notes, it just acclimatises you to the durations.
On the second cycle you will see blips during the dark phase. In the light phase, click or tap to make blops, to match the number of blips. You'll quickly find that unless you have superhuman counting skills it's easier to just follow the rhythm.
There's also phrasing and improv in-built into the game. Every four bars you get a new theme, and for each bar in the next four bars, the Conductor improvises on the melody by adding new notes that fit with the theme's rhythm.
Man, game jams are great to learn new tech! I had always wanted to try using web audio, and this was the perfect opportunity. The most useful article wrt this was by Chris Wilson here.
And of course, this whole idea of counting -> rhythm, is a riff of that Rhythm Heaven mini-game, adapted to fit the one-bit criteria!