I think Facebook accepts a zip too. To be honest their rules aren't very clear and in some cases are self-defeating: the requirement to put everything in a single HTML file actually makes the file size larger, due to base64 encoding, and if you aren't allowed to zip the HTML file then obviously you'll have a larger file size too. So if you can, use a zip, but a single HTML file should still only be 30% larger or so than an equivalent web export even without compression.
yeah, strange requirements
if zip is ok, so, the limit is 5 MB there
Ashley, you did a really great job, playable ads export works well, and exported games also work well even with effects
I will promote C3 in the telegram channels for gamedevs