The contents of the menu are excellent; however, there are a few problems:
The background color does not contrast well enough with the screen background (if you do not want to change the color, you might want to add a border). (I am using an LCD monitor)
If you move the mouse pointer down, then the entire menu sometimes closes just before or on "Recognized Chess Variants" as the "Play.Chessvariants.org" submenu is closing. (In Mozilla-based browser)
I have one other suggestion which you might or might not like:
Change the ALT text of the logo graphic to "Menu" (or something containing "Menu") so that it is clear when images are disabled, what that means.
The contents of the menu are excellent; however, there are a few problems:
I have one other suggestion which you might or might not like: