I think there should be clarification in the instructions about what constitutes an "island nation." I went back and forth on both UK and Ireland because I know they are located on islands, but each has a land border with the other, so I wasn't sure whether that would disqualify them. Very fun quiz though.
I don't think we need clarification on that. Island nations are nations that are completely located on islands (excluding dependent territories). If just the land border would affect the status as an island country, then Indonesia wouldn't be considered an island country. That would make no sense, to me at least
Got Portugal in the Mediterranean wrong. And I thought that was the easiest category, didn't think it through