Can you share your Hype document too?
I have a feeling it's related to your images and the size of the output (it's coming in at over 6MB).
Don't quote me on this though I'm just speculating. I need more info. While testing there was an error thrown which said "Can't find variable 'startTimeline..." but can't seem to reproduce it.
If you can share your document. It would be easier to see what's been done.
I would also suggest making a version specifically for mobile devices too. So that one can see the buttons and image without have to zoom in. (You can create a separate layout in Hype)
Sorry I can't be of more help at this time.