A 'simple' way (depending on how much data you have on countries!) could be for example something like: 1st it's bigger than France, 2nd it's in Africa, 3rd it's more densely populated than.... Is it ok if I copy your idea?
I think that you may have better knowledge on countries, so that's fine if you are going to run multi-country quizzes of this idea. But please start your series after I have released the 5th quiz in my series. I will move to other categories (capitals, US states, elements of the periodic table, etc.) then, and I may run multi-answer series myself for elements of the periodic table.
As long as there are no parts of this country lying on the mainland Asia, that's fine. I'm going to change the words "the archipelago" (which is singular) back to my initial "islands" (which is plural), however.