You get six guesses to find the secret country. Unknown names and repeated guesses do not use one up, and a wrong sixth guess reveals the answer.
Six guesses is the whole game. A win shows how many you needed, and the share result records it as, for example, 4/6.
If a name is not recognised or you repeat a country, you are told and keep the guess.
See also How distance is measured. For tips, read the Closer or Farther tips and strategy.