YEAAAA that's exactly what I feared too T.T
It's not just you, for some reason the web build can get very inconsistent across multiple browsers. For some it desyncs the audio horribly, for others it works fine. Unfortunately it runs fine on every browser I've tried so far and it drives me nuts I can't reproduce the issue! I've also had folks try it on the browser of their mobile phone and it ran fine... yea this one's hard to track down.
Glad to hear the PC version of the game ran fine though! Happy you enjoyed it :D