I am wondering if background videos in IOS would work in the current version of Hype. I know that there was some mentioned about this in the release notes. Mine doesn't seem to be working but not sure if it's unsupported.
Inline video is a new method for allowing videos to play on the page without going full screen or behind other elements: http://tumult.com/hype/documentation/3.0/#controlling-video
I recommend also turning off 'Controls'