var Enemy_3 = Container.expand(function (spawnerInstance, gameInstance) {
	var self = Container.call(this);
	self.gameInstance = gameInstance;
	var enemyGraphics = self.createAsset('enemy_3', 'Enemy_3 Graphics', .5, .5);
	self.speed = 7;
	self.move = function () {
		self.y += self.speed;
	};
	self.on('down', function () {
		self.destroyEnemy();
	});
	self.destroyEnemy = function () {
		self.destroy();
		self.gameInstance.updateCoins(1);
		self.gameInstance.enemies = self.gameInstance.enemies.filter(function (e) {
			return e !== self;
		});
	};
});
var Enemy = Container.expand(function (spawnerInstance, gameInstance) {
	var self = Container.call(this);
	self.gameInstance = gameInstance;
	var enemyGraphics = self.createAsset('enemy', 'Enemy Graphics', .5, .5);
	self.speed = 3;
	self.move = function () {
		self.y += self.speed;
	};
	self.on('down', function () {
		self.destroyEnemy();
	});
	self.destroyEnemy = function () {
		self.destroy();
		self.gameInstance.updateCoins(1);
		self.gameInstance.enemies = self.gameInstance.enemies.filter(function (e) {
			return e !== self;
		});
	};
});
var Tower = Container.expand(function () {
	var self = Container.call(this);
	self.scheduleNextSnowball = function () {};
	self.isActive = false;
	self.level = 1;
	self.upgradeCost = 10;
	self.snowballSpeed = 5;
	self.activationCost = 10;
	self.upgradeTower = function () {
		if (self.gameInstance.coins >= self.upgradeCost) {
			self.gameInstance.coins -= self.upgradeCost;
			self.level += 1;
			if (self.level === 2) {
				self.isActive = true;
				self.shootSnowball();
			} else if (self.level > 2) {
				self.snowballSpeed += 1;
				if (self.gameInstance.bullets.length > 0) {
					self.gameInstance.bullets[0].speed = self.snowballSpeed;
				}
			}
			self.upgradeCost += 5;
			self.gameInstance.updateCoins(0);
			self.gameInstance.towerCostText.setText(self.upgradeCost.toString());
		}
		if (self.gameInstance.coins < self.upgradeCost) {
			console.log('Not enough coins to upgrade the tower');
		}
		self.alpha = 1;
	};
	self.shootSnowball = function () {
		if (self.isActive && self.gameInstance.bullets.length === 0) {
			var snowball = new Snowball(self.snowballSpeed);
			snowball.x = self.x;
			snowball.y = self.y + 80;
			self.gameInstance.bullets.push(snowball);
			self.parent.addChild(snowball);
		}
	};
});
var Snowball = Container.expand(function (speed) {
	var self = Container.call(this);
	self.speed = speed;
	var snowballGraphics = self.createAsset('snowball', 'Snowball Graphics', .5, .5);
	self.speed = speed;
});
var Base = Container.expand(function () {
	var self = Container.call(this);
	self.health = 100;
	self.updateHealth = function () {};
});
var Enemy_2 = Container.expand(function (spawnerInstance, gameInstance) {
	var self = Container.call(this);
	self.gameInstance = gameInstance;
	var enemyGraphics = self.createAsset('enemy_2', 'Enemy_2 Graphics', .5, .5);
	self.speed = 5;
	self.move = function () {
		self.y += self.speed;
	};
	self.on('down', function () {
		self.destroyEnemy();
	});
	self.destroyEnemy = function () {
		self.destroy();
		self.gameInstance.updateCoins(1);
		self.gameInstance.enemies = self.gameInstance.enemies.filter(function (e) {
			return e !== self;
		});
	};
});
var Spawner = Container.expand(function (x, y) {
	var self = Container.call(this);
	var spawnerGraphics = self.createAsset('spawner', 'Spawner Graphics', .5, .5);
	self.x = x;
	self.y = y;
	self.enemyWeights = {
		'Enemy': 80,
		'Enemy_2': 13,
		'Enemy_3': 6,
		'total': 99,
		'bucket': []
	};
	self.resetEnemyBucket = function () {
		for (var key in self.enemyWeights) {
			if (key !== 'total' && key !== 'bucket') {
				for (var i = 0; i < self.enemyWeights[key]; i++) {
					self.enemyWeights.bucket.push(key);
				}
			}
		}
	};
	self.resetEnemyBucket();
	self.spawnEnemy = function () {
		if (self.enemyWeights.bucket.length === 0) {
			self.resetEnemyBucket();
		}
		var randomIndex = Math.floor(Math.random() * self.enemyWeights.bucket.length);
		var chosenEnemy = self.enemyWeights.bucket.splice(randomIndex, 1)[0];
		var enemy;
		switch (chosenEnemy) {
			case 'Enemy':
				enemy = new Enemy(self, self.parent);
				break;
			case 'Enemy_2':
				enemy = new Enemy_2(self, self.parent);
				break;
			case 'Enemy_3':
				enemy = new Enemy_3(self, self.parent);
				break;
		}
		if (!enemy) throw new Error('Invalid enemy type: ' + chosenEnemy);
		enemy.x = self.x + 20;
		enemy.y = self.y + 250;
		self.parent.enemyLayer.addChild(enemy);
		self.parent.enemies.push(enemy);
	};
});
var Game = Container.expand(function () {
	var self = Container.call(this);
	self.shootSnowball = function () {
		if (self.tower) {
			self.tower.shootSnowball();
		}
	};
	self.towerButton = self.createAsset('towerButton', 'Tower Button', .5, .5);
	self.towerButton.x = 2048 / 2 - 900;
	self.towerButton.y = 1800 - 1300;
	var towerCenterX = self.towerButton.x + self.towerButton.width * 0.5;
	var towerCenterY = self.towerButton.y + self.towerButton.height * 0.5;
	self.towerButton.on('down', function () {
		if (self.tower) {
			self.tower.upgradeTower();
		}
	});
	LK.gui.addChild(self.towerButton);
	var background = self.createAsset('background', 'Game Background', 0, 0);
	background.width = LK.stage.width;
	background.height = LK.stage.height;
	var GUI = self.createAsset('GUI', 'GUI Asset', 0.5, 0.5);
	GUI.x = 1024;
	GUI.y = 3650;
	self.addChild(GUI);
	var Coin = self.createAsset('coin', 'Coin Asset', 0.5, 0.5);
	Coin.x = 124;
	Coin.y = 2620;
	self.addChild(Coin);
	self.GUI = GUI;
	self.coins = 0;
	self.coinDisplay = new Text2('0', {
		size: 100,
		fill: "#ffffff",
		align: 'center',
		stroke: '#000000',
		strokeThickness: 6
	});
	self.coinDisplay.anchor.set(0, 0.5);
	self.coinDisplay.x = 170;
	self.coinDisplay.y = 1840;
	LK.gui.addChild(self.coinDisplay);
	self.removeCoinDisplay = function () {
		LK.gui.removeChild(self.coinDisplay);
	};
	var towerCost = 10;
	self.towerCostText = new Text2(towerCost.toString(), {
		size: 70,
		fill: "#ffffff",
		align: 'center',
		stroke: '#000000',
		strokeThickness: 8
	});
	self.towerCostText.anchor.set(0.5, 0.5);
	self.towerCostText.x = self.towerButton.x;
	self.towerCostText.y = self.towerButton.y;
	self.towerCostText.alpha = 0;
	var BuyBtn = self.createAsset('buyButton', 'Buy Button', 0.5, 0.5);
	BuyBtn.x = towerCenterX - 140;
	BuyBtn.y = towerCenterY - 80;
	BuyBtn.alpha = 0;
	BuyBtn.on('down', function () {
		if (self.tower) {
			self.tower.upgradeTower();
		}
	});
	LK.gui.addChild(BuyBtn);
	LK.gui.addChild(self.towerCostText);
	self.updateCoins = function (coinIncrement) {
		self.coins += coinIncrement;
		self.coinDisplay.setText(self.coins.toString());
		if (self.coins >= self.tower.upgradeCost) {
			BuyBtn.alpha = 1;
			self.towerCostText.alpha = 1;
		} else {
			BuyBtn.alpha = 0;
			self.towerCostText.alpha = 0;
		}
		if (self.tower) {
			self.towerButton.alpha = 1;
		}
	};
	self.enemies = [];
	var base = self.addChild(new Base());
	self.bullets = [];
	self.snowballSpeed = 7;
	self.initializeTowers = function () {
		var numberOfTowers = 5;
		var towerWidth = LK.getAsset('tower', 'Tower Asset', 0.5, 0.5).width;
		var spacing = (LK.stage.width - numberOfTowers * towerWidth) / (numberOfTowers + 1);
		var xPosition = spacing;
		self.towers = [];
		for (var i = 0; i < numberOfTowers; i++) {
			var tower = self.addChild(new Tower());
			tower.x = xPosition;
			tower.y = LK.stage.height - tower.height / 2 - 100;
			tower.gameInstance = self;
			self.towers.push(tower);
			xPosition += towerWidth + spacing;
		}
	};
	self.initializeTowers();
	base.x = 2048 / 2;
	base.y = 2732 - base.height / 2;
	self.enemyLayer = new Container();
	self.addChild(self.enemyLayer);
	var spawner1 = new Spawner(2048 / 6 + 200, -200);
	var spawner2 = new Spawner(2048 / 2 + 100, -200);
	var spawner3 = new Spawner(2048 / 6 * 5, -200);
	self.addChild(spawner1);
	self.addChild(spawner2);
	self.addChild(spawner3);
	var spawner1Timer = LK.setInterval(function () {
		spawner1.spawnEnemy();
	}, 3000);
	spawner1.spawnEnemy();
	var spawner2Timer = LK.setInterval(function () {
		spawner2.spawnEnemy();
	}, 2500);
	spawner2.spawnEnemy();
	var spawner3Timer = LK.setInterval(function () {
		spawner3.spawnEnemy();
	}, 2000);
	spawner3.spawnEnemy();
	LK.on('tick', function () {
		self.enemies.forEach(function (enemy) {
			enemy.move();
			if (enemy.y + enemy.height / 2 >= LK.stage.height) {
				self.removeCoinDisplay();
				LK.showGameOver();
			}
		});
		self.bullets.forEach(function (snowball) {
			snowball.x += snowball.speed;
			self.enemies.forEach(function (enemy) {
				if (snowball.intersects(enemy)) {
					enemy.destroyEnemy();
					self.bullets = self.bullets.filter(function (b) {
						return b !== snowball;
					});
					snowball.destroy();
					if (self.tower.isActive) {
						self.tower.shootSnowball();
					}
				}
			});
			if (snowball.x > LK.stage.width) {
				self.bullets = self.bullets.filter(function (b) {
					return b !== snowball;
				});
				snowball.destroy();
				if (self.tower.isActive) {
					self.tower.shootSnowball();
				}
			}
		});
	});
});

===================================================================
--- original.js
+++ change.js
@@ -1,42 +1,4 @@
-var SnowballManager = Container.expand(function (gameInstance) {
-	var self = Container.call(this);
-	self.gameInstance = gameInstance;
-	self.shootSnowball = function () {
-		if (self.gameInstance.tower && self.gameInstance.tower.isActive) {
-			var snowball = new Snowball(self.gameInstance.tower.snowballSpeed);
-			snowball.x = self.gameInstance.tower.position.x;
-			snowball.y = self.gameInstance.tower.position.y + 80;
-			self.gameInstance.bullets.push(snowball);
-			self.gameInstance.addChild(snowball);
-		}
-	};
-	self.handleCollisions = function () {
-		self.gameInstance.bullets.forEach(function (snowball) {
-			self.gameInstance.enemies.forEach(function (enemy) {
-				if (snowball.intersects(enemy)) {
-					enemy.destroyEnemy();
-					self.gameInstance.bullets = self.gameInstance.bullets.filter(function (b) {
-						return b !== snowball;
-					});
-					snowball.destroy();
-					if (self.gameInstance.tower.isActive) {
-						self.shootSnowball();
-					}
-				}
-			});
-			if (snowball.x > LK.stage.width) {
-				self.gameInstance.bullets = self.gameInstance.bullets.filter(function (b) {
-					return b !== snowball;
-				});
-				snowball.destroy();
-				if (self.gameInstance.tower.isActive) {
-					self.shootSnowball();
-				}
-			}
-		});
-	};
-});
 var Enemy_3 = Container.expand(function (spawnerInstance, gameInstance) {
 	var self = Container.call(this);
 	self.gameInstance = gameInstance;
 	var enemyGraphics = self.createAsset('enemy_3', 'Enemy_3 Graphics', .5, .5);
@@ -73,14 +35,10 @@
 			return e !== self;
 		});
 	};
 });
-var Tower = Container.expand(function (initialX, initialY) {
+var Tower = Container.expand(function () {
 	var self = Container.call(this);
-	self.position = {
-		x: initialX,
-		y: initialY
-	};
 	self.scheduleNextSnowball = function () {};
 	self.isActive = false;
 	self.level = 1;
 	self.upgradeCost = 10;
@@ -91,12 +49,15 @@
 			self.gameInstance.coins -= self.upgradeCost;
 			self.level += 1;
 			if (self.level === 2) {
 				self.isActive = true;
+				self.shootSnowball();
 			} else if (self.level > 2) {
 				self.snowballSpeed += 1;
+				if (self.gameInstance.bullets.length > 0) {
+					self.gameInstance.bullets[0].speed = self.snowballSpeed;
+				}
 			}
-			self.gameInstance.snowballManager.shootSnowball();
 			self.upgradeCost += 5;
 			self.gameInstance.updateCoins(0);
 			self.gameInstance.towerCostText.setText(self.upgradeCost.toString());
 		}
@@ -105,12 +66,12 @@
 		}
 		self.alpha = 1;
 	};
 	self.shootSnowball = function () {
-		if (self.isActive) {
+		if (self.isActive && self.gameInstance.bullets.length === 0) {
 			var snowball = new Snowball(self.snowballSpeed);
-			snowball.x = self.position.x;
-			snowball.y = self.position.y + 80;
+			snowball.x = self.x;
+			snowball.y = self.y + 80;
 			self.gameInstance.bullets.push(snowball);
 			self.parent.addChild(snowball);
 		}
 	};
@@ -193,9 +154,13 @@
 	};
 });
 var Game = Container.expand(function () {
 	var self = Container.call(this);
-	self.snowballManager = new SnowballManager(self);
+	self.shootSnowball = function () {
+		if (self.tower) {
+			self.tower.shootSnowball();
+		}
+	};
 	self.towerButton = self.createAsset('towerButton', 'Tower Button', .5, .5);
 	self.towerButton.x = 2048 / 2 - 900;
 	self.towerButton.y = 1800 - 1300;
 	var towerCenterX = self.towerButton.x + self.towerButton.width * 0.5;
@@ -273,12 +238,24 @@
 	self.enemies = [];
 	var base = self.addChild(new Base());
 	self.bullets = [];
 	self.snowballSpeed = 7;
-	self.tower = self.addChild(new Tower());
-	self.tower.position.x = towerCenterX;
-	self.tower.position.y = towerCenterY;
-	self.tower.gameInstance = self;
+	self.initializeTowers = function () {
+		var numberOfTowers = 5;
+		var towerWidth = LK.getAsset('tower', 'Tower Asset', 0.5, 0.5).width;
+		var spacing = (LK.stage.width - numberOfTowers * towerWidth) / (numberOfTowers + 1);
+		var xPosition = spacing;
+		self.towers = [];
+		for (var i = 0; i < numberOfTowers; i++) {
+			var tower = self.addChild(new Tower());
+			tower.x = xPosition;
+			tower.y = LK.stage.height - tower.height / 2 - 100;
+			tower.gameInstance = self;
+			self.towers.push(tower);
+			xPosition += towerWidth + spacing;
+		}
+	};
+	self.initializeTowers();
 	base.x = 2048 / 2;
 	base.y = 2732 - base.height / 2;
 	self.enemyLayer = new Container();
 	self.addChild(self.enemyLayer);
@@ -307,7 +284,30 @@
 				self.removeCoinDisplay();
 				LK.showGameOver();
 			}
 		});
-		self.snowballManager.handleCollisions();
+		self.bullets.forEach(function (snowball) {
+			snowball.x += snowball.speed;
+			self.enemies.forEach(function (enemy) {
+				if (snowball.intersects(enemy)) {
+					enemy.destroyEnemy();
+					self.bullets = self.bullets.filter(function (b) {
+						return b !== snowball;
+					});
+					snowball.destroy();
+					if (self.tower.isActive) {
+						self.tower.shootSnowball();
+					}
+				}
+			});
+			if (snowball.x > LK.stage.width) {
+				self.bullets = self.bullets.filter(function (b) {
+					return b !== snowball;
+				});
+				snowball.destroy();
+				if (self.tower.isActive) {
+					self.tower.shootSnowball();
+				}
+			}
+		});
 	});
 });