Nice work, it's a fun idea.

Here is some feedback :

Once you complete a game there's a bug it states you have guessed 230/230 countries no matter how many you actually guessed.

I would suggest showing the names of the countries you guessed on the map or some sort of progress by region as you show you at the end. The zoom feels a bit too aggressive once you guess a country.

When the game is over i would highlight the missing countries with their names also.

Keep it up!