First of all, you can type any letter of the alphabet. Every nation that isn't part of the Commonwelth will appear. Then you have to guess all countries that are members of the Commonwealth of Nations to bring them back to land.
This is a good quiz, really neat! The only thing I noticed (besides the fact that Eswatini doesn't work for Swaziland) was that having all of the lakes made it kinda confusing. I thought I was missing a country in Africa and couldn't figure out what it was, and it was actually just Lake Victoria.