Game in question: dl.dropboxusercontent.com/u/8262744/WormMP/index.html
Right now it depends on the music playing to actually become playable, which is silly and I'll fix it, but why doesn't it play anything in other browsers like Firefox or Internet Explorer? I searched a bit and it seems Construct 2 is supposed to convert files to two fromats to support most browsers (I used .ogg files made in Audacity), so this shouldn't be a problem, right?
You should rather export your song as .wav from Audacity, and then import that into Construct, which will then automatically convert the .wav to .ogg and .m4a formats, which covers all the platforms.
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It can't convert .ogg to .m4a or the other way around either. It does Convert Wav 16 bit PCM files to both.
Or, you can make your own .m4a with the same name as your .ogg, and import it as well.