OOPS this was meant for your best practices thread. Sorry I put it here by mistake.
I have posted it over there on your best practices thread just now too.
There are definitely some important things to keep in mind. I've done a lot of web exports and basically audio format is important for both music and sounds. I can't remember which I ended up going with and am out to breakfast right now.
Also from what I found in my experiments some browsers (or at least versions) seem to limit the numher of simultaneously playing sounds to 16 or possibly it was even 8 in one case. It didn't stop new sounds from playing but previous sounds were cut off.
For frame rate independent timing you want to use milliseconds. The function I most often see people use and perhaps even in official examples does not work in html5. Always returns 0.
Like I said I am out eating so that is all off the top of my head but I can take a look later today.
My best suggestion is just do a ton of experiments. That is what I did and do.
TI/994a (BASIC) -> C64 (BASIC/PASCAL/ASM/Others) -> Amiga (AMOS/BLITZ/ASM/C/Gamesmith) -> DOS (C/C++/Allegro) -> Windows (C++/C#/Monkey X/GL Basic/Unity/Others)