var GrayHeart = Container.expand(function () {
	var self = Container.call(this);
	var grayHeartGraphics = self.createAsset('grayHeart', 'Gray Heart icon', 0, 0);
});
var Heart = Container.expand(function () {
	var self = Container.call(this);
	var heartGraphics = self.createAsset('heart', 'Heart icon', 0, 0);
});
var Santa = Container.expand(function () {
	var self = Container.call(this);
	var santaGraphics = self.createAsset('santa', 'Santa character', .5, .5);
	self.move = function () {};
	self.collect = function () {};
});
var Gift = Container.expand(function () {
	var self = Container.call(this);
	var giftGraphics = self.createAsset('gift', 'Gift item', .5, .5);
	self.drop = function () {
		self.y += 5;
	};
});
var Game = Container.expand(function () {
	var self = Container.call(this);
	var score = 0;
	var scoreTxt = new Text2(score.toString(), {
		size: 150,
		fill: "#ffffff"
	});
	scoreTxt.anchor.set(.5, 0);
	LK.gui.topCenter.addChild(scoreTxt);
	var lives = 3;
	var hearts = [];
	for (var i = 0; i < lives; i++) {
		var heart = new Heart();
		heart.x = i * (heart.width + 10);
		heart.y = 10;
		hearts.push(heart);
		LK.gui.topLeft.addChild(heart);
	}
	var santa = self.addChild(new Santa());
	var gifts = [];
	santa.x = 2048 / 2;
	santa.y = 2732 - santa.height;
	var giftCreationInterval = LK.setInterval(function () {
		var gift = new Gift();
		gift.x = Math.random() * 2048;
		gift.y = 0;
		gifts.push(gift);
		self.addChild(gift);
	}, 2000);
	LK.on('tick', function () {
		santa.move();
		for (var i = 0; i < gifts.length; i++) {
			gifts[i].drop();
			if (santa.intersects(gifts[i])) {
				santa.collect(gifts[i]);
				score++;
				scoreTxt.setText(score.toString());
				gifts[i].destroy();
				gifts.splice(i, 1);
				i--;
				if (hearts.length > 0) {
					var lostHeart = hearts.pop();
					lostHeart.destroy();
				}
			} else if (gifts[i].y > 2732) {
				gifts[i].destroy();
				gifts.splice(i, 1);
				i--;
				if (--lives <= 0) {
					LK.showGameOver();
				} else if (hearts.length > 0) {
					var lostHeart = hearts.pop();
					lostHeart.destroy();
					var grayHeart = new GrayHeart();
					grayHeart.x = lostHeart.x;
					grayHeart.y = lostHeart.y;
					LK.gui.topLeft.addChild(grayHeart);
				}
			}
		}
	});
	stage.on('down', function (obj) {
		var pos = obj.event.getLocalPosition(self);
		santa.x = pos.x;
	});
	stage.on('move', function (obj) {
		var pos = obj.event.getLocalPosition(self);
		santa.x = pos.x;
	});
});

===================================================================
--- original.js
+++ change.js
@@ -1,7 +1,7 @@
 var GrayHeart = Container.expand(function () {
 	var self = Container.call(this);
-	var grayHeartGraphics = self.createAsset('grayHeart', 'Gray heart icon', 0, 0);
+	var grayHeartGraphics = self.createAsset('grayHeart', 'Gray Heart icon', 0, 0);
 });
 var Heart = Container.expand(function () {
 	var self = Container.call(this);
 	var heartGraphics = self.createAsset('heart', 'Heart icon', 0, 0);
@@ -58,26 +58,25 @@
 				scoreTxt.setText(score.toString());
 				gifts[i].destroy();
 				gifts.splice(i, 1);
 				i--;
-			} else if (gifts[i] && gifts[i].y > 2732) {
+				if (hearts.length > 0) {
+					var lostHeart = hearts.pop();
+					lostHeart.destroy();
+				}
+			} else if (gifts[i].y > 2732) {
 				gifts[i].destroy();
 				gifts.splice(i, 1);
 				i--;
-				if (gifts[i] && gifts[i].y > 2732) {
-					gifts[i].destroy();
-					gifts.splice(i, 1);
-					i--;
-					if (--lives <= 0) {
-						LK.showGameOver();
-					} else {
-						var grayHeart = new GrayHeart();
-						grayHeart.x = hearts[hearts.length - 1].x;
-						grayHeart.y = hearts[hearts.length - 1].y;
-						LK.gui.topLeft.addChild(grayHeart);
-						var lostHeart = hearts.pop();
-						lostHeart.destroy();
-					}
+				if (--lives <= 0) {
+					LK.showGameOver();
+				} else if (hearts.length > 0) {
+					var lostHeart = hearts.pop();
+					lostHeart.destroy();
+					var grayHeart = new GrayHeart();
+					grayHeart.x = lostHeart.x;
+					grayHeart.y = lostHeart.y;
+					LK.gui.topLeft.addChild(grayHeart);
 				}
 			}
 		}
 	});