Works on Android. Trying it on regular Firefox on Pinephone Pro results in:

> This page is slowing down Firefox. To speed up your browser, stop this page.

Weirdly, the image animation doesn't render until I hit the "Debug Script" button that Firefox presents, which pauses execution. It's only with the JS paused that the animation begins.

The pause is at the `for (; b < a + 60; )` loop that works an OscillatorNode. I guess a sound is supposed to be played. I checked youtube and sound works. I guess this loop prevents the firing of whatever event the animation depends on.

Loop terminates. It's just really slow. Only once it ends does the sound happen (haven't used OscillatorNodes before; probably normal).