Great! I found many pictures were too hard - some because of my ignorance but for some I wonder whether somethings more 'representative' would be better, although personally for some I have no idea what would be!
Nice quiz! Some small states are really hard to guess, so maybe a bit more time could be used for guessing.
Some countries are really easy to recognize, others could have a bit more famous picture, e.g. Switzerland which - if I see it right - is just a mountain village view. That can be found in many countries in the Alps and maybe even elsewhere. (Better: Picture of Matterhorn or Zürich)
Also, Latvia I didn't get although I once was up on the tower of that church. (Better: Riga old town panorama view or the freedom monument).
Some of the photo pics are just plain bad, like Congo. There are definitely more recognizable things you could have included (animals, features of landscape, satellite images, big cities). The pacific islands all being beaches doesn't even give us a chance to go on anything and we have to guess. And for that kind of guessing the time is too short.
I don't believe that you weren't able to find any landmarks for so many countries. I guess that a lot of these photos aren't recognizable even for the people who live in these countries. Every country has something distinguishable, at least in the capital city. You had a great idea with this quiz but I believe that you can fix it.
1. Some countries, such as the Pacific Islands, look very similar.
2. Some countries, such as Guinea-Bissau, have no features easily recognizable.
Some countries are really easy to recognize, others could have a bit more famous picture, e.g. Switzerland which - if I see it right - is just a mountain village view. That can be found in many countries in the Alps and maybe even elsewhere. (Better: Picture of Matterhorn or Zürich)
Also, Latvia I didn't get although I once was up on the tower of that church. (Better: Riga old town panorama view or the freedom monument).
Still, I applaud the endeavour.