Start by typing any letter to get the first country coloured. Type the first 3 letters of this country: another one will get coloured, type its first 3 letters... and so on, all the way!
Countries smaller than 150,000 km2 are not considerd in this quiz, so the smallest one you have to watch out for is TUNisia
Any chance you would consider making the newest country a different color than green? It's hard to see which one is in question. Other than that, GREAT quiz.