This game includes the flags of the 3rd to 11th most populous cities in the Russian Federation. Please note that Moscow and St. Petersburg are not included in this game. This is because they were featured in one of my previous games (Federal cities of Russia - flags).
Kazan flag image attribution:
By "AlexTref871" [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons