Google Insights is really weird. It showed 37 for mobiles but 91 for desktop for me.
The one thing that is obvious - your images are very large for the first page. Just use this service for example to minify your png’s. This will cut page size in about a half at minimum, increasing some vital stats for insights.
Another advice that insights give you (never seen this on my own pages btw) is to basically simplify your layout as in less nesting. This is kinda broad and not very clear advice which may require complete refactoring of the page and is not exactly easy to do I guess.
I think sinply reducing all your assets sizes will do much to score better. Give it a try!
edit: do not forget about your intro video! almost 4mb is insane. Reduce the size and quality to make it less than 1mb at least