I suggest adding yellow boxes and/or reducing the time. I don't watch the olympics but got 5/5 with plenty of time to spare by typing countries with a decent size population where it snows quite a bit!
I like easy quizzes. I like them because they make me feel good and because lots of people take them. Too easy for you? Try to name as many popes as you can.
You can always go for your own speed record, or even look at the statistics to compare your time to others if you want to be competitive. Why would you want to reduce the time so that other people are not able to complete all the boxes?
The ranking should not be sorted by total medal count, but by number of gold medals first, then silver, then bronze. This is how the IOC publishes their list, and what's used within sport circles (it's better a single gold medal that five silvers). See:https://en.wikipedia.org/wiki/2018_Winter_Olympics_medal_table
Norway's population is 5.2 million. That is smaller than the population of the Philadelphia metro area. It's remarkable what the Norwegians have accomplished in the Winter games.