/**** 
* Classes
****/
// Grizzly Bear class
var GrizzlyBear = Container.expand(function () {
	var self = Container.call(this);
	var bearGraphics = self.createAsset('grizzlyBear', 'Grizzly Bear running', 0.5, 1);
	self.isJumping = false;
	self.jumpHeight = 1500;
	self.jumpSpeed = 20;
	self.gravity = 2;
	self.jump = function () {
		if (!self.isJumping) {
			self.isJumping = true;
			self.jumpSpeed = -50;
		}
	};
	self.fall = function () {
		if (self.isJumping) {
			self.jumpSpeed += self.gravity;
			self.y += self.jumpSpeed;
			if (self.y >= 2832 - self.height) {
				self.y = 2832 - self.height;
				self.isJumping = false;
			}
		}
	};
});
// Tree class
var Tree = Container.expand(function () {
	var self = Container.call(this);
	var treeGraphics = self.createAsset('tree', 'Background tree', 0.5, 1);
	self.speed = 1;
	self.move = function () {
		self.x -= self.speed;
		if (self.x < -self.width) {
			self.destroy();
		}
	};
});
// Lemming class
var Lemming = Container.expand(function () {
	var self = Container.call(this);
	var lemmingGraphics = self.createAsset('lemming', 'Lemming running away', 0.5, 1);
	self.speed = 3;
	self.move = function () {
		self.x -= self.speed;
		if (self.x < -self.width) {
			self.destroy();
		}
	};
});
// Rock class
var Rock = Container.expand(function () {
	var self = Container.call(this);
	var rockGraphics = self.createAsset('rock', 'Obstacle rock', 0.5, 1);
	self.speed = 2;
	self.move = function () {
		self.x -= self.speed;
		if (self.x < -self.width) {
			self.destroy();
		}
	};
});

/**** 
* Initialize Game
****/
var game = new LK.Game({
	backgroundColor: 0x87CEEB // Sky blue background
});

/**** 
* Game Code
****/
// Initialize important asset arrays and score
var lemmings = [];
var trees = [];
var score = 0;
var rocks = [];
var grizzlyBear;
// Create the Grizzly Bear
grizzlyBear = game.addChild(new GrizzlyBear());
grizzlyBear.x = 100;
grizzlyBear.y = 2732 - grizzlyBear.height + 100;
// Create score display
var scoreTxt = new Text2(score.toString(), {
	size: 150,
	fill: "#ffffff"
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Game tick event
LK.on('tick', function () {
	// Spawn Trees at intervals
	if (LK.ticks % 800 === 0) {
		var newTree = new Tree();
		newTree.x = 2048;
		newTree.y = 2732 - newTree.height + 300;
		trees.push(newTree);
		game.addChildAt(newTree, 0);
	}
	// Make the Grizzly Bear fall
	grizzlyBear.fall();
	// Move each Lemming and check for collision with GrizzlyBear
	for (var i = lemmings.length - 1; i >= 0; i--) {
		lemmings[i].move();
		// Check if Lemming collides with GrizzlyBear and remove it
		if (grizzlyBear.intersects(lemmings[i])) {
			// Increase score by 10 when Grizzly Bear catches a Lemming
			score += 10;
			lemmings[i].destroy();
			lemmings.splice(i, 1);
			continue;
		}
		// Check if Lemming is off screen and destroy it
		if (lemmings[i].x < -lemmings[i].width) {
			lemmings[i].destroy();
			lemmings.splice(i, 1);
		}
	}
	// Move each Rock
	for (var i = rocks.length - 1; i >= 0; i--) {
		rocks[i].move();
		// Check if Rock collides with GrizzlyBear and end the game
		if (grizzlyBear.intersects(rocks[i])) {
			LK.showGameOver();
		}
		// Check if Rock is off screen and destroy it
		if (rocks[i].x < -rocks[i].width) {
			rocks[i].destroy();
			rocks.splice(i, 1);
		}
	}
	// Move each Tree
	for (var i = trees.length - 1; i >= 0; i--) {
		trees[i].move();
		// Check if Tree is off screen and destroy it
		if (trees[i].x < -trees[i].width) {
			trees[i].destroy();
			trees.splice(i, 1);
		}
	}
	// Update score display text
	scoreTxt.setText(score.toString());
	// Spawn Rocks at intervals
	if (LK.ticks % 1200 === 0) {
		var newRock = new Rock();
		newRock.x = 2048;
		newRock.y = 2732 - newRock.height;
		rocks.push(newRock);
		game.addChildAt(newRock, game.children.length);
	}
	// Spawn Lemmings at intervals
	if (LK.ticks % 240 === 0) {
		var newLemming = new Lemming();
		newLemming.x = 2048;
		newLemming.y = 2732 - newLemming.height;
		lemmings.push(newLemming);
		game.addChildAt(newLemming, game.children.length);
	}
});
// Touch event for Grizzly Bear to jump
game.on('down', function () {
	grizzlyBear.jump();
});

===================================================================
--- original.js
+++ change.js
@@ -146,11 +146,11 @@
 	// Spawn Rocks at intervals
 	if (LK.ticks % 1200 === 0) {
 		var newRock = new Rock();
 		newRock.x = 2048;
-		newRock.y = 2732 - newRock.height + 300;
+		newRock.y = 2732 - newRock.height;
 		rocks.push(newRock);
-		game.addChildAt(newRock, 0);
+		game.addChildAt(newRock, game.children.length);
 	}
 	// Spawn Lemmings at intervals
 	if (LK.ticks % 240 === 0) {
 		var newLemming = new Lemming();