all sorts of errors in my workspace

  public class Game 
  public static final int MAX_MISSES = 7;
  private String mAnswer;
  private String mHits;
  private String mMisses;


  public Game(String answer) {
  mAnswer = answer;
  mHits = "";
  mMisses = "";  
  }

  private char validateGuess(char letter) {
    if (! Character.isLetter(letter)) {
     throw new IllegalArgumentException("A letter is required"); 
    }
  }
  letter = Character.toLowerCase(letter);
  if (mMisses.indexOf(letter) >= 0 || (mHits.indexOf(letter) >= 0) {
    throw new IllegalArgumentException(letter + "has already been guessed");
    return letter;
      }
  public boolean applyGuess(String letter) {
    if (letters.length() == 0) {
      throw new IllegalArgumentException("No letter found");
    }

    return applyGuess(letters.charAt(0));
  }    

  public boolean applyGuess(char letter) {
    letter = validateGuess(letter);
    boolean isHit = mAnswer.indexOf(letter) >= 0;
    if (isHit) {
      mHits += letter;
    } else {
      mMisses += letter;
    }
}    
public String getCurrentProgress() {
  String progress = "";
  for (char letter: mAnswer.toCharArray()) {
   char display = '-';
    if (mHits.indexOf(letter) >= 0)
      display = letter;
  }
progress += display;

return progress;
}

public int getRemainingTries() {
  return MAX_MISSES - mMisses.length();
}


public String getAnswer() {
  return mAnswer;
}

public boolean isSolved() {
  return getCurrentProgress().indexOf('-') == -1;
}```

import java.io.Console;

public class Prompter {
  private Game mGame;

  public Prompter(Game game) {
    mGame = game;
  }

  public void play() {
    while (mGame.getRemainingTries > 0 && !mGame.isSolved()) {
      displayProgress();
      promptForGuess();
    }
    if (mGame.isSolved()) {
      System.out.printf("Congratulations you won with %d tries remaining!\n",mGame.getRemainingTries());
    } else {
      System.out.printf('Bummer the word was %s. :(\n",
                        mGame.getAnswer());
    }
  }  



  public boolean promptForGuess() {
   Console console = System.console();
   boolean isHit = false;
   boolean isValidGuess = false;
   while (! isValidGuess) { 
   String guessAsString = console.readLine("Enter a letter:  ");
   try {
     isHit = mGame.applyGuess(guessAsString);
     isValidGuess = true;
   } catch (IllegalArgumentException iae) {
     console.printf("%s. Please try again. \n", iae.getMessage());
}
   }
    return isHit;
  }
public void displayProgress() {
  System.out.printf("You have %d tries left to solve: %s\n",
                    mGame.getRemainingTries(),
                    mGame.getCurrentProgress());
}



}