Citydle covers 2,300+ major world cities. Classic attribute matrix mode: continent, country, hemisphere and population are compared. Population gets a directional arrow.
The city list comes from the GeoNames open dataset: every one of the 2,400+ cities above 250,000 people can be typed as a guess. The answer comes from the roughly 270 best-known: the most-read world cities on Wikipedia plus 25 Turkish provincial capitals.
You can search cities by their English, Turkish or Spanish name.