How to fix js function bug in HTML game?

Question

JavaScript

Hello. Faced a bug in a function when creating a game. The game itself seems to work correctly, but when restarting (pressing the "start again" button), the function does not work correctly, namely, it does not end. I ended it by writing return, and also tried to return a value from it and use it, but also without result. Because of this, when the game is restarted, this function is not restarted, but duplicated, and when you click on the alphabet button, the click goes as many times as the function was launched, the wrong and right variables are not redefined, which causes incorrect actions. This is the game() function.

At the first game everything works fine, at the next ones it doesn't work well I'll

attach a link to the code of the entire project

'use strict';

window.addEventListener('DOMContentLoaded', () => {

    const words = ['Компьютер', 'Программа', 'Клавиатура', 'Монитор', 'Мышь', 'Микрофон', 'Дисковод'];

    const btnStart = document.querySelector('.btn__start'),
          subtitle = document.querySelector('.subtitle'),
          title = document.querySelector('.title'),
          alphabet = document.querySelector('.alphabet'),
          alphabetLetters = document.querySelectorAll('.alphabet__word'),
          wordsItem = document.querySelector('.words'),
          bodyItem = document.querySelectorAll('.body-item');


    // get random word from array
    function randomWord(arr) {
        const i = Math.floor(Math.random() * arr.length);
        const word = arr[i];
        return word;
    }

    // create blocks with letters
    function createBlocks(word) {
        let blocks = word.toLowerCase().split('');
        const elements = [];
        for (let i = 0; i < blocks.length; i++) {
            let w = document.createElement('div');
            w.classList.add('word');
            w.textContent = blocks[i];
            elements.push(w);
        }
        elements.forEach(e => wordsItem.append(e));
        return elements;
    }

    // get blocks with right letter
    function getBlock(letter, blocks) {
        let b = [];
        blocks.forEach(block => {
            if (block.textContent === letter.value) {
                b.push(block);
            }
        });
        return b;
    }

    // start our game
    function startGame() {
        btnStart.style.display = 'none';
        alphabet.style.cssText = `
        transform: translate(0%, -50%);
        opacity: 1;
    `;
        title.textContent = 'Добро пожаловать на казнь!';
        title.style.color = '#b40000';
        subtitle.textContent = 'Выберите букву';
    }

    // playing game
    function game() {
        startGame();
        let wrong = 0,
            right = 0;
        // word from array and blocks with letters
        let gameWord = randomWord(words),
            gameBlocks = createBlocks(gameWord);

        console.log(gameWord);

        alphabetLetters.forEach(letter => {
            letter.style.cssText = `text-transform: uppercase;`;

//с этого места начинается баг

            letter.addEventListener('click', (e) => {
                e.preventDefault();
                const target = e.target;
                let rightAnswer = getBlock(target, gameBlocks);
                if (rightAnswer.length > 0) {
                    target.style.backgroundColor = 'rgb(116, 224, 72)';
                    target.disabled = true;
                    rightAnswer.forEach(answ => {
                        answ.style.cssText = `
                        font-size: 20px;
                        text-transform: uppercase;
                    `;
                    });
                    right += rightAnswer.length;
                    if (right === gameWord.length) {
                        winGame();
                        return;
                    }
                } else {
                    bodyItem[wrong].style.opacity = '1';
                    wrong++;
                    target.disabled = true;
                    target.style.backgroundColor = 'rgb(255, 72, 72)';
                    if (wrong === 6) {
                        loseGame(gameBlocks);
                        return;
                    }
                }
            });
        });
    }

    function endGame() {
        alphabetLetters.forEach(l => {
            l.disabled = true;
        });
        btnStart.style.display = 'block';
        btnStart.textContent = 'Начать заново';
        btnStart.classList.remove('btn__start');
        btnStart.classList.add('btn__restart');
    }

    function winGame() {
        endGame();
        title.textContent = 'Победа!';
        title.style.color = 'rgb(0, 255, 85)';
        subtitle.textContent = 'Вы обманули смерть';
    }

    function loseGame(gameBlocks) {
        endGame();
        title.textContent = 'Поражение!';
        title.style.color = 'rgb(255, 43, 43)';
        subtitle.textContent = 'Смерть настигла вас';
        gameBlocks.forEach(item => {
            item.style.cssText = `
            font-size: 20px;
            text-transform: uppercase;
            `;
        });
        const message = document.createElement('p');
        message.textContent = 'Было загадано слово';
        wordsItem.insertAdjacentElement('beforebegin', message);
    }

    function restart() {
        bodyItem.forEach(item => {
            item.style.opacity = '0';
        });
        alphabetLetters.forEach(letter => {
            letter.disabled = false;
            letter.style.backgroundColor = 'rgb(243, 255, 79)';
        });
        document.querySelectorAll('.word').forEach(word => {
            word.remove();
        });
        game();
    }


    btnStart.addEventListener('click', () => {
        if (btnStart.classList.contains('btn__start')) {
            game();
        } else if (btnStart.classList.contains('btn__restart')) {
            restart();
        }
    });
});