Fully playable prototype of “Plus+Plus” built in JavaScript using only jQuery

Talking about Plus+Plus game, Game development and Javascript.

Did you play Plus+Plus? Described as an “hidden gem” by TouchArcade, it’s a simple and funny number puzzle. The game is played on a 5×5 grid, and the numbers one to six – but they will increase as you progress with the game – to fit into the grid making horizontal or vertical rows of the same number. You can stack numbers on top of each other, but only once. As usual, this is the kind of game which would take me an hour to explain, while you can understand in a minute by playing it on your own:
Click on a tile to place a number or stack a number on top of another number. You can’t stack on top of red numbers. Rows or columns filled with the same numbers will disappear. I made the entire game with no game oriented frameworks, using only JavaScript and jQuery. Moreover, I did not use arrays to store board information, I am checking tile contents by reading its inner HTML. The game features score, increases difficulty and shows you the three next numbers you have to place on the grid. All game elements are rendered with HTML, using good old tables and cascading style sheets like this one: 
body{
    margin: 0;
    padding: 5px;
    background-color: #2c3e50;
    color: #ecf0f1;
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    -khtml-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}
#tilecontainer{
    width:360px;
    margin: 0px auto;
}
.tile{
    width: 60px;
    height: 60px;
    border: 1px solid #7f8c8d;
    margin: 5px;
    cursor: pointer;
    text-align: center;
    font: bold 32px arial;
    line-height: 60px;
}
#nextTile1{
    width: 60px;
    height: 60px;
    border: 1px solid #16a085;
    margin: 5px;
    cursor: pointer;
    text-align: center;
    font: bold 32px arial;
    color: #16a085;
    line-height: 60px;
}
.smallTile{
    width:30px;
    height: 30px;
    border: 1px solid #7f8c8d;
    margin: 34px 5px 5px 5px;
    float: left;
    color: #7f8c8d;
    text-align: center;
    font: bold 16px arial;
    line-height: 30px;
}
#allowedNumbers{
    margin: 5px;
    font: normal 16px arial;
}
#score{
    margin: 5px;
    font: normal 24px arial;
    text-align: right;
}
.greenTile{
    color: #16a085;
    border-color: #16a085;
}
.redTile{
    color: #e74c3c;
    border-color: #e74c3c;
}
Then, the JavaScript part which also adds all game elements. 
$(document).ready(function(){
    var maxNumber = 6;
    var score = 0;
    drawBoard();
    updateGUI(maxNumber, score);
    drawNumbers(maxNumber, true);
    $('.tile').click(function(){
        var legalMove = false;
        var row = $(this).data('row');
        var col = $(this).data('col');
        if($(this).html() == ''){
            $(this).html($('#nextTile1').html()).addClass('greenTile');
            legalMove = true;
        }
        else{
            if($(this).hasClass('greenTile')){
                $(this).html(parseInt($(this).html()) + parseInt($('#nextTile1').html())).removeClass('greenTile').addClass('redTile');
                legalMove = true;
            }
        }
        if(legalMove){
            score += parseInt($('#nextTile1').html());
            score += removeTiles(row, col);
            maxNumber = updateGUI(maxNumber, score);
            $('#nextTile1').html($('#nextTile2').html());
            $('#nextTile2').html($('#nextTile3').html());
            drawNumbers(maxNumber, false);
        }
    })
})

function removeTiles(row, col){
    var score = 0;
    if(removeRow(row)){
        for(i = 0; i < 5; i++){
            score += parseInt($('.tile[data-row = "' + row + '"][data-col = "' + i + '"]').html());
            $('.tile[data-row = "' + row + '"][data-col = "' + i + '"]').html("").removeClass('greenTile').removeClass('redTile');
        }
    }
    if(removeCol(col)){
        for(i = 0; i < 5; i++){
            score += parseInt($('.tile[data-row = "' + i + '"][data-col = "' + col + '"]').html());
            $('.tile[data-row = "' + i + '"][data-col = "' + col + '"]').html("").removeClass('greenTile').removeClass('redTile');
        }
    }
    return score;
}

function removeRow(row){
    var value = $('.tile[data-row = "' + row + '"][data-col = "' + 0 + '"]').html();
    if(value == ""){
        return false
    }
    for(var i = 1; i < 5; i++){
        if($('.tile[data-row = "' + row + '"][data-col = "' + i + '"]').html() != value){
            return false;
        }
    }
    return true;
}

function removeCol(col){
    var value = $('.tile[data-row = "' + 0 + '"][data-col = "' + col + '"]').html();
    if(value == ""){
        return false;
    }
    for(var i = 1; i < 5; i++){
        if($('.tile[data-row = "' + i + '"][data-col = "' + col + '"]').html() != value){
            return false;
        }
    }
    return true;
}

function updateGUI(n, s){
    if(s > n * (n - 1) * (n - 2)){
        n ++;
    }
    var html = "";
    for(var i = 1; i <= n; i++){
            html += " " + i;
    }
    $('#allowedNumbers').html(html);
    $('#score').html(s);
    return n;
}

function drawBoard(){
    var tableHTML = '<table cellspacing = "0" cellpadding = "0" border = "0">';
    for(var i = -2; i < 6; i++){
        tableHTML += '<tr>';
        for(var j = 0; j < 5; j++){
            switch(i){
                case -2:
                    switch(j){
                        case 0:
                        case 1:
                            tableHTML += '<td></td>';
                            break;
                        case 2:
                            tableHTML += '<td><div id = "nextTile1"></div></td>';
                            break;
                        case 3:
                            tableHTML += '<td colspan = "2"><div class = "smallTile" id = "nextTile2"></div><div class = "smallTile" id = "nextTile3"></div><div style = "clear:both"></div></td>';
                            break;
                    }
                    break;
                case -1:
                    if(j == 1){
                        tableHTML += '<td colspan = "5"><div id = "allowedNumbers"></div></td>';
                    }
                    break;
                case 5:
                    if(j == 1){
                        tableHTML += '<td colspan = "5"><div id = "score"></div></td>';
                    }
                    break;
                default:
                    tableHTML += '<td><div class = "tile" data-row = "' + i + '" data-col = "' + j + '"></div></td>';
            }
        }
        tableHTML += '</tr>';
    }
    tableHTML += '</table>';
    $("#tilecontainer").html(tableHTML);
}

function drawNumbers(max, firstRun){
    var n = Math.floor(Math.random() * max) + 1;
    $('#nextTile3').html(n);
    if(firstRun){
        n = Math.floor(Math.random() * max) + 1;
        $('#nextTile2').html(n);
        n = Math.floor(Math.random() * max) + 1;
        $('#nextTile1').html(n);
    }
}
The code is not commented because it’s just a jQuery experiment, but I’ll translate it into something more interesting using Phaser and Panda, meanwhile you can download the source code.