game.js

var buttonColours = ["red", "blue", "green", "yellow"];
var gamePattern = [];
var userClickedPattern = [];

var started = false;

var level = 0;

$(document).keypress(function () {
    if (!started) {

        $("#level-title").text("Level " + level);
        nextSequence();
        started = true;
    }
});

$(".btn").click(function () {

    var userChosenColour = $(this).attr("id");
    userClickedPattern.push(userChosenColour);
    animatePress(userChosenColour)
    playSound(userChosenColour);

    checkAnswer(userClickedPattern.length - 1);
});

function checkAnswer(currentLevel) {

    
    if (gamePattern[currentLevel] === userClickedPattern[currentLevel]) {

        if (userClickedPattern.length === gamePattern.length) {

            setTimeout(function () {
                nextSequence();
            }, 1000);

        }

    } else {

        playSound("wrong");

        $("body").addClass("game-over")
        setTimeout(function () {
            $("body").removeClass("game-over")
        }, 200);
        
        $("#level-title").text("Game Over, Press Any Key to Restart");

        startOver();
        console.log("wrong");

    }

}

function nextSequence() {

    userClickedPattern = [];

    level++;

    $("#level-title").text("Level " + level);

    var randomNumber = Math.floor(Math.random() * 4);
    var randomChosenColour = buttonColours[randomNumber];
    gamePattern.push(randomChosenColour);

    $("#" + randomChosenColour).fadeIn(100).fadeOut(100).fadeIn(100);

    playSound(randomChosenColour);
}

function playSound(name) {

    var audio = new Audio("sounds/" + name + ".mp3");
    audio.play();
}

function animatePress(currentColor) {

    $("#" + currentColor).addClass("pressed");

    setTimeout(function () {
        $("#" + currentColor).removeClass("pressed");
    }, 100);
}

function startOver() {

    //3. Inside this function, you'll need to reset the values of level, gamePattern and started variables.
    level = 0;
    gamePattern = [];
    started = false;
  }