There's no point in uploading your entire game; I doubt anybody would download 500MB then trawl through it to find your issue.
Your best bet is to try to first try to isolate the problem in your game: Save a copy of your game and strip out all the visuals and extra stuff, leaving just the audio. If the problem persists, keep stripping out stuff until it goes away. At that point, you should be able to figure out exactly what's causing the trouble - it's very likely to be just an error in your code, maybe an endless loop or something else sucking up resources.
If none of that is fruitful, test it on multiple browsers, as well as node-webkit. And if you've got access to another PC, test it on that, too.