条件，逻辑运算符未按预期执行

Question

if条件未在我的代码中按预期执行。函数isPlaying由下面的eventListener调用时显示函数的状态为＆＃39;播放＆＃39;即使this.guesses变量= 0，并且在guesses = -1时更改为已完成或失败，这会导致额外的按键显示已完成或失败的消息。如果我将条件更改为this.guesses＆gt; 1状态立即更改。我很困惑。

    const Hangman = function(word,guesses){
    this.word = word.toLowerCase().split(''),
    this.guesses = guesses,
    this.guessedLetters = []
    this.status = 'playing';
}

Hangman.prototype.isPlaying = function(){
    const isWordMissing = this.wordPuzzle().includes('*');
    if(this.guesses > 0 && isWordMissing){
        this.status = 'playing';
    }else if(this.guesses > 0.5 && !isWordMissing){
        this.status = 'finished';
    }
    else if(this.guesses === 0){
        this.status = 'failed';
    }
}
Hangman.prototype.wordPuzzle = function(){
    let puzzle = ''
        this.word.forEach((letter) => {
            if(this.guessedLetters.includes(letter) || letter === ' '){
                puzzle += letter;
            }else{
                puzzle += '*';
            }
        })
        return puzzle;
}
Hangman.prototype.guessLetters = function(letter){
    guess = letter.toLowerCase();
    const isUnique = !this.guessedLetters.includes(letter.toLowerCase());
    const isBadGuess = !this.word.includes(letter.toLowerCase());

    if(!this.guessedLetters.includes(letter.toLowerCase())){
        this.guessedLetters.push(letter);
    }
    if(isUnique && isBadGuess){
        this.guesses = this.guesses - 1;
    }
}

game = new Hangman('fast',3);
const puzzleEl = document.querySelector('#word');
const guessEl = document.querySelector('#guess-left')
puzzleEl.textContent = game.wordPuzzle();   
guessEl.textContent = `Guesses remaining: ${game.guesses}`;
console.log(game.status);

window.addEventListener('keypress', (e) => {
    if(game.status !== 'playing'){
        console.log(game.status)
    }
    else{
    const guess = String.fromCharCode(e.charCode);
    game.guessLetters(guess);  
    puzzleEl.textContent = game.wordPuzzle();   
    guessEl.textContent = `Guesses remaining: ${game.guesses}` 
    debugger;
    game.isPlaying()
    }      
})