Code
Something that I did recognize is that in the navigation they use a nav class of header-nav and li id menu-item with a specific number, and something that I didn't seen before is anchor class with an href of a image. Another is polygon class is something we never were shown with a svg.
UI
The UI is well simple to use and easy for anyone to use it for education purposes. It is like it say: "light-fit custom web applications. with no fuss."
UX
It is fun and entertainment and easy to understand.
Summary
Overall, Envy Labs has done a great job with their homepage. The Developer Experiance (DX) could be improved somewhat, but, other than that, there are no signifitcant problems. I had fun going over this webpage.