non-static method promptForGuess()

  public class Hangman { 

    public static void main(String[] args) {
        // Enter amazing code here:
      Game game = new Game("treehouse");
      Prompter prompter = new Prompter(game);
      boolean isHit = Prompter.promptForGuess();
      if(isHit){
        System.out.println("We got a hit");
      }else{
        System.out.println("Whoops miss");
      }
    }
}

import java.io.Console;

public class Prompter {
  private Game mGame;
  public Prompter(Game game){
    mGame= game; 
  }
public boolean promptForGuess(){
  Console console = System.console();
  String guessAsString = console.readLine("Enter a letter: ");
  char guess = guessAsString.charAt(0);
  return mGame.applyGuess(guess);
}

}