Full page modal menus can work but the key is simplicity. There are several “famous” ones out there and they all follow this simple formula of a few large font size links. If you have a more complex site structure and many links then it probably isn’t the most readable or intuitive style for users.
Once of the most famous ones is the huge Inc site, and in this context it works well. The rest of the content links (which are almost like blog articles) are further down the page in the masonry type layout section