Javascript Event Listener Issue

I'm making a small quiz game in Javascript and have come across an issue with one of the event listeners. I have a $form event listener to check the answer entered by the user, which calls a check() function. I can play the game through once, however when I want to play it again, things go wrong because of the event listener I think. I attempted moving the $form event listener where I have the $start and $again event listeners, however then I have the issue on how to access check() methodThis should be all the relevant code. I have this code working when it wasn't object oriented but I'm a little stuck here as I was switching it over. My question is how can I get the event listener to properly work where it is located in the code currently OR if it is moved with the other event listeners, how can I access the check() method? This should be the relevant code. Any assistance would be greatly appreciated!

//// DOM REFERENCES ////
//// Common convention to begin DOM variables with $ ////
var $question = document.getElementById("question");
var $score = document.getElementById("score");
var $feedback = document.getElementById("feedback");
var $start = document.getElementById("start");
var $form = document.getElementById("answer");
var $again = document.getElementById("again");
var $timer = document.getElementById("timer");

//Initializations
quiz = {
    "name": "Harry Potter Quiz",
    "description": "How well do you know the books/movies?",
    //"question": "What is that real name of ",
    "questions": [
        {"question": "What is Harry Potter's House?", "answer": "Gryffendor", "asked": false},
        {"question": "With What did Harry catch his first Snitch?", "answer": "Mouth", "asked": false},
        {"question": "Which potion do Harry, Ron, and Hermione take in year 2?", "answer": "Polyjuice", "asked": false}
    ]
};
var score = 0;
var interval = 0;
var i = 0;

//// View Functions ////
function update(element, content, klass) {
    //'element' is element to be updated
    //'content' is content to be updated with
    //A class can be added to content being added --> klass
    var p = element.firstChild || document.createElement("p");
    p.textContent = content;
    element.appendChild(p);
    if (klass) {
        p.className = klass;
    }
}

function hide(element) {
    element.style.display = "none";
}

function show(element) {
    element.style.display = "block";
}

function random(a, b, callback) {
    if (b === undefined) {
        //If only one argument is supplied, assme the lower limit is 1
        b = a;
        a = 1;
    }
    var result = Math.floor((b - a + 1) * Math.random()) + a;
    if (typeof callback === "function") {
        result = callback(result);
    }
    return result;
}

//=============================================================//

//Event Listeners
$start.addEventListener("click", function() { new Game(quiz) }, false);
$again.addEventListener("click", function() { new Game(quiz); 
                                         update($feedback, "", "clear");
                                         show($feedback) }, false);
//Hide the form at the start of the game
hide($form);
hide($again);

function Game(quiz){
    //Hide button and show form
    hide($start);
    hide($again);
    show($form);
    this.questions = quiz.questions;
    this.phrase = quiz.qustion;
    this.score = 0;
    update($score, this.score);


    //Initialize time and set up interval that counts down
    this.time = 20;
    update($timer, this.time);
    this.interval = window.setInterval(this.countDown.bind(this), 1000);

    //Add event listener to form for when it's submitted
    $form.addEventListener("submit", function(event) { 
        event.preventDefault();
        this.check($form[0].value);
    }.bind(this), false);

    this.chooseQuestion();
}

//Method Definitions
Game.prototype.chooseQuestion = function() {
    var questions = this.questions.filter(function(question){
        return question.asked === false;
    });
    //set the current question
    this.question = questions[random(questions.length) - 1];
    this.ask(this.question);
}

Game.prototype.ask = function(question){
    var quiz = this;
    alert(quiz.questions.length);
    //set the question.asked property to true so it's not asked again
    question.asked = true;
    update($question, question.question);
    $form[0].value = "";
    $form[0].focus();

    //clear previoues options
    //$form.innerHTML = "";
}

Game.prototype.check = function(answer){
    if(answer === this.question.answer){
        update($feedback, "Correct!", "right");
        //increase score by 1
        this.score++;
        update($score, this.score);
    } else {
        update($feedback, "Wrong!", "wrong");
    }
    i++;
    if(i === quiz.questions.length){
        this.gameOver();
    } else { 
        this.chooseQuestion();
    }
    //this.chooseQuestion();
}