only missed the micronations and vanuatu. And new guinea, but well, it doesnt accept new guinea I had tried it, a few times actually (I know it is not the official name but that is always accepted on quizzes and is what people usually call it). Actually had about 5 names that werent accepted here which normally were accepted. Cote d'ivoire being one of them.
I dont think this quiz should have different rules. It messes you up quite a lot, because often you think you have already done a certain country..