This looks cool, but the website is a good example of design ignoring "the fold" causing confusion. I spent about 30 seconds staring at the three tiny blocks of text below the menu options before I realized that I could scroll down.
Even if you can't see more than the 3 boxes on the page, you have a scroll bar and a large, softly pulsating link that says "Sign up now, it's free ↴". And if you don't scroll down, all of the navigation is right there at the top anyway.
I'm glad they ignored the fold, and I think all designers should aspire to this level of quality and attention to detail in their own work.
Maybe some sort of visual cue or "bridge" would encourage scrolling, like stepping the paragraphs, or using an alternating left-right text-graphic layout.