Here’s our guide for decreasing load speeds: Decreasing load times and optimizing performance: Preparing a Large project in Hype
By default, Hype will preload all images and only begin displaying your document after all images have been loaded. You can control this behavior on a per-image basis by disabling the Preload option that’s presented in your document’s Resource Library when an image is selected. This will probably give you the biggest speed boost.
It does look some there’s some extra style information present in your .html document, but it should have a huge effect on loading time.