You need to specify that this is city proper, not urban. The Wikipedia article notes that, for instance, New Delhi is smaller than Mumbai (250k vs. 12M), but the Delhi metropolitan area is larger (21M vs. 20M).
Without that information, no one would guess the Philippines, since Quezon City and Manila are in the same metro area, or Liechtenstein (Vaduz and Schaan are part of the same metro area), or Malta, or San Marino, or Taiwan (Taipei and New Taipei).
City of Brussels has less than 200k which is much less than Antwerp with over 500k. It clearly says "city proper" in the description and not urban/metro area.
"Since independence, urbanization has sprawled eastward past Pikine, a commuter suburb whose population (2001 est. 1,200,000) is greater than that of Dakar proper"
Israel could be added, if you are consistent in your source. If you however add information outside of your own quoted source, than Jerusalem (+East Jerusalem) would be bigger than Tel Aviv. Still don't understand why Belgium is excluded.
"Jerusalem would be Israel's largest city if East Jerusalem were to be included (increasing the population to 936,425), however the annexation of East Jerusalem into Israel is not internationally recognized. If East Jerusalem were to be excluded from Israel, Tel Aviv would be the largest city." I don't know if that changes anything, but I think it depends on whether or not you recognize the annexation.
Good quiz, I liked it. Just a little thing, I use the black mode so I don’t know if this is for everyone. But the white colour is a bit confusing, because quizzes usually fit to your style, that’s why I guess that you manually coloured it white. Specific tiles are also white which made me thing there are more nations missing, just remove the white paint
Without that information, no one would guess the Philippines, since Quezon City and Manila are in the same metro area, or Liechtenstein (Vaduz and Schaan are part of the same metro area), or Malta, or San Marino, or Taiwan (Taipei and New Taipei).
Biggest city -> Antwerp
Capital -> Brussels (in city proper is less populate than Antwerp)