===================================================================
--- original.js
+++ change.js
@@ -1,73 +1,73 @@
-/****
+/**** 
 * Classes
 ****/
 // Hero class
 var Hero = Container.expand(function () {
-  var self = Container.call(this);
-  var heroGraphics = self.attachAsset('hero', {
-    anchorX: 0.5,
-    anchorY: 0.5
-  });
-  self.update = function () {
-    // Hero update logic
-  };
-  self.shoot = function () {
-    // Hero shooting logic
-  };
+	var self = Container.call(this);
+	var heroGraphics = self.attachAsset('hero', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.update = function () {
+		// Hero update logic
+	};
+	self.shoot = function () {
+		// Hero shooting logic
+	};
 });
 // Enemy class
 var Enemy = Container.expand(function () {
-  var self = Container.call(this);
-  var enemyGraphics = self.attachAsset('enemy', {
-    anchorX: 0.5,
-    anchorY: 0.5
-  });
-  self.speed = 2;
-  self.move = function () {
-    self.y += self.speed;
-  };
-  self.shoot = function () {
-    // Enemy shooting logic
-  };
+	var self = Container.call(this);
+	var enemyGraphics = self.attachAsset('enemy', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.speed = 2;
+	self.move = function () {
+		self.y += self.speed;
+	};
+	self.shoot = function () {
+		// Enemy shooting logic
+	};
 });
 // Bullet class for hero
 var HeroBullet = Container.expand(function () {
-  var self = Container.call(this);
-  var bulletGraphics = self.attachAsset('heroBullet', {
-    anchorX: 0.5,
-    anchorY: 0.5
-  });
-  self.speed = -10;
-  self.move = function () {
-    self.y += self.speed;
-  };
+	var self = Container.call(this);
+	var bulletGraphics = self.attachAsset('heroBullet', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.speed = -10;
+	self.move = function () {
+		self.y += self.speed;
+	};
 });
 // Bullet class for enemies
 var EnemyBullet = Container.expand(function () {
-  var self = Container.call(this);
-  var bulletGraphics = self.attachAsset('enemyBullet', {
-    anchorX: 0.5,
-    anchorY: 0.5
-  });
-  self.speed = 5;
-  self.move = function () {
-    self.y += self.speed;
-  };
+	var self = Container.call(this);
+	var bulletGraphics = self.attachAsset('enemyBullet', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.speed = 5;
+	self.move = function () {
+		self.y += self.speed;
+	};
 });
 
-/****
+/**** 
 * Initialize Game
 ****/
 var game = new LK.Game({
-  backgroundColor: 0x000000 // Init game with black background
+	backgroundColor: 0x000000 // Init game with black background
 });
 
-/****
+/**** 
 * Game Code
 ****/
-// Initialize hero
 // Define assets for the hero, enemies, and bullets
+// Initialize hero
 var hero = game.addChild(new Hero());
 hero.x = 2048 / 2;
 hero.y = 2732 - 150;
 // Initialize arrays for bullets and enemies
@@ -75,51 +75,64 @@
 var enemyBullets = [];
 var enemies = [];
 // Game tick event
 LK.on('tick', function () {
-  // Update hero
-  hero.update();
-  // Move and check hero bullets
-  for (var i = heroBullets.length - 1; i >= 0; i--) {
-    heroBullets[i].move();
-    if (heroBullets[i].y < 0) {
-      heroBullets[i].destroy();
-      heroBullets.splice(i, 1);
-    }
-  }
-  // Move and check enemy bullets
-  for (var j = enemyBullets.length - 1; j >= 0; j--) {
-    enemyBullets[j].move();
-    if (enemyBullets[j].y > 2732) {
-      enemyBullets[j].destroy();
-      enemyBullets.splice(j, 1);
-    }
-  }
-  // Move enemies and check for game over
-  for (var k = enemies.length - 1; k >= 0; k--) {
-    enemies[k].move();
-    if (enemies[k].y > 2732) {
-      LK.showGameOver();
-    }
-  }
-  // Spawn enemies
-  if (LK.ticks % 120 == 0) {
-    var newEnemy = new Enemy();
-    newEnemy.x = Math.random() * (2048 - newEnemy.width) + newEnemy.width / 2;
-    newEnemy.y = -newEnemy.height / 2;
-    enemies.push(newEnemy);
-    game.addChild(newEnemy);
-  }
+	// Update hero
+	hero.update();
+	// Move and check hero bullets
+	for (var i = heroBullets.length - 1; i >= 0; i--) {
+		heroBullets[i].move();
+		for (var k = enemies.length - 1; k >= 0; k--) {
+			if (heroBullets[i] && heroBullets[i].intersects(enemies[k])) {
+				heroBullets[i].destroy();
+				heroBullets.splice(i, 1);
+				enemies[k].destroy();
+				enemies.splice(k, 1);
+				break;
+			}
+		}
+		if (heroBullets[i] && heroBullets[i].y < 0) {
+			heroBullets[i].destroy();
+			heroBullets.splice(i, 1);
+		}
+	}
+	// Move and check enemy bullets
+	for (var j = enemyBullets.length - 1; j >= 0; j--) {
+		enemyBullets[j].move();
+		if (enemyBullets[j].intersects(hero)) {
+			LK.effects.flashScreen(0xff0000, 1000);
+			LK.showGameOver();
+		}
+		if (enemyBullets[j] && enemyBullets[j].y > 2732) {
+			enemyBullets[j].destroy();
+			enemyBullets.splice(j, 1);
+		}
+	}
+	// Move enemies and check for game over
+	for (var k = enemies.length - 1; k >= 0; k--) {
+		enemies[k].move();
+		if (enemies[k].y > 2732) {
+			LK.showGameOver();
+		}
+	}
+	// Spawn enemies
+	if (LK.ticks % 120 == 0) {
+		var newEnemy = new Enemy();
+		newEnemy.x = Math.random() * (2048 - newEnemy.width) + newEnemy.width / 2;
+		newEnemy.y = -newEnemy.height / 2;
+		enemies.push(newEnemy);
+		game.addChild(newEnemy);
+	}
 });
 // Touch event to move hero
 game.on('down', function (obj) {
-  var pos = obj.event.getLocalPosition(game);
-  hero.x = pos.x;
+	var pos = obj.event.getLocalPosition(game);
+	hero.x = pos.x;
 });
 // Touch event to shoot
 game.on('up', function (obj) {
-  var bullet = new HeroBullet();
-  bullet.x = hero.x;
-  bullet.y = hero.y - hero.height / 2;
-  heroBullets.push(bullet);
-  game.addChild(bullet);
+	var bullet = new HeroBullet();
+	bullet.x = hero.x;
+	bullet.y = hero.y - hero.height / 2;
+	heroBullets.push(bullet);
+	game.addChild(bullet);
 });
\ No newline at end of file