var score = 0;
var color = "blue";

function random(min,max){
     return Math.round(Math.random() * (max-min) + min);
}

function setBG(){
  if (Math.round(Math.random())){
    return "http://icons.iconarchive.com/icons/hopstarter/halloween-avatars/128/Frankenstein-icon.png";
  } else {
    return "http://icons.iconarchive.com/icons/hopstarter/halloween-avatars/128/Scream-icon.png";
  }
}



function dropBox(){
  var length = random(100, ($(".game").width() - 100));
  var velocity = random(850, 10000);
  var size = random(50, 150);
  var thisBox = $("<div/>", {
    class: "box",
    style:  "width:" +size+ "px; height:"+size+"px; left:" + length+  "px; transition: transform " +velocity+ "ms linear;"
  });
  
  //set data and bg based on data
  thisBox.data("test", Math.round(Math.random()));
  if(thisBox.data("test")){
    thisBox.css({"background": "url('http://icons.iconarchive.com/icons/hopstarter/halloween-avatars/128/Frankenstein-icon.png')", "background-size":"contain"});
  } else {
    thisBox.css({"background": "url('http://icons.iconarchive.com/icons/hopstarter/halloween-avatars/128/Scream-icon.png')", "background-size":"contain"});
  }
  
  
  //insert gift element
  $(".game").append(thisBox);
  
  //random start for animation
  setTimeout(function(){
    thisBox.addClass("move");
  }, random(0, 5000) );
  
  //remove this object when animation is over
  thisBox.one("webkitTransitionEnd otransitionend oTransitionEnd msTransitionEnd transitionend",
              function(event) {
    $(this).remove();
  });
}

for (i = 0; i < 10; i++) {
  dropBox();
}

$(document).on('click', '.box', function(){

  
  if($(this).data("test")){
    score += 1;
  } else {
    score -= 1;
  }
  
  $(".score").html(score);
  $(this).remove();
});

var runGame = setInterval(function(){
                for (i = 0; i < 10; i++) {
                  dropBox();
                }  
              }, 5000);

function countdown() {
        var seconds = 60;
        function tick() {
            var counter = document.getElementById("counter");
            seconds--;
            counter.innerHTML = (seconds < 10 ? "0" : "")  + String(seconds) + "S";
            if( seconds > 0 ) {
                setTimeout(tick, 1000);
                draw();
                   update();
            } else {
                alert("Game over");
                clearInterval(runGame);
            }
        }
        tick();
    }

countdown();

Bu kodlardaki icon'ların sayısını arttırmanın yolu var mı? Mesela farklı iconlar eklemek istesem? Rica etsem?