How could I improve design of my website?

Very cute content.
I understand that you want a conventional horizontal menu like along the top, and a floating menu which stays visible as you scroll, but that floating menu is taking a lot of realestate, can a compromise be organised ?
I like the odd/even colour scheme.
Like the spaciness between elements, feel that some line to line spaces could be tighter.

I like the idea, but it would be much better without the floating menu widget on the side. People aren’t so lazy that they won’t scroll to the top to navigate. A good idea would be to implement a (small) floating “To the top” button that users can click and be guided to the navigation bar, instead of the widget you have.