This was a really interesting quiz! I spent two minutes trying to figure out the last answer, but I almost missed Indonesia because I thought I had already guessed it... but I did it with 8 seconds to spare.
I had two seconds left, and I just randomly decided to type 'France,' I was shocked to get 100% off a guess like that, but when I thought about it, it made a lot of sense, :)
I was playing this just as the coastline bit and got 19/21 lol. Didn't even realize or process that the caveat says 'borders included' so I missed D.R Congo and Kazakstan
I think there should be a note marking that autonomous regions count, since I almost missed Denmark. Also, I think its cool that even small countries like PNG can get on it due to their islands.