/**** 
* Plugins
****/ 
var tween = LK.import("@upit/tween.v1");

/**** 
* Classes
****/ 
var Bird = Container.expand(function () {
	var self = Container.call(this);
	var birdGraphics = self.attachAsset('bird', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.xSpeed = 10.9375;
	self.ySpeed = -20;
	self.gravity = 1;
	self.lift = -15;
	self.flap = function () {
		self.ySpeed = self.lift * 1.5;
		LK.getSound('flap').play();
	};
	self.update = function () {
		if (game.isMouseDown) {
			self.ySpeed += self.gravity / 3;
		} else {
			self.ySpeed += self.gravity;
		}
		self.y += self.ySpeed;
		self.x += self.xSpeed;
		if (self.y <= 0 || self.y >= 2732) {
			self.speed = -self.speed;
		}
		var targetRotation = Math.atan2(self.ySpeed, self.xSpeed * self.scale.x) / 2;
		birdGraphics.rotation += (targetRotation - birdGraphics.rotation) / 10;
	};
	self.flip = function () {
		self.scale.x *= -1;
	};
});
var Obstacle = Container.expand(function () {
	var self = Container.call(this);
	var obstacleShadow = self.attachAsset('obstacleShadow', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	obstacleShadow.rotation = Math.PI / 4;
	var obstacleShadow2 = self.attachAsset('obstacleShadow2', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	obstacleShadow2.rotation = Math.PI / 4;
	obstacleShadow2.y = -7;
	var obstacleGraphics = self.attachAsset('obstacle', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	obstacleGraphics.rotation = Math.PI / 4;
	self.speed = 5;
	self.update = function () {
		self.y += game.obstacleSpeed;
	};
});
var Wall = Container.expand(function () {
	var self = Container.call(this);
	var wallGraphics = self.attachAsset('wall', {
		anchorX: 0.5,
		anchorY: 0.5
	});
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x330000
});

/**** 
* Game Code
****/ 
var tutorialTextWhite = new Text2('Tap to Flap\nHold to Float', {
	size: 150,
	fill: '#ffffff',
	font: 'Impact',
	align: 'center'
});
tutorialTextWhite.anchor.set(.5, 1);
tutorialTextWhite.x = -4;
tutorialTextWhite.y = -62;
LK.gui.bottom.addChild(tutorialTextWhite);
var tutorialText = new Text2('Tap to Flap\nHold to Float', {
	size: 150,
	fill: '#ff4444',
	font: 'Impact',
	dropShadow: true,
	dropShadowColor: '#990000',
	dropShadowBlur: 5,
	dropShadowDistance: 7,
	dropShadowAngle: 0,
	align: 'center'
});
tutorialText.anchor.set(.5, 1);
tutorialText.y = -50;
LK.gui.bottom.addChild(tutorialText);
game.score = 0;
game.obstacleSpeed = 5;
game.obstacleSpeedIncrease = 0.005;
game.checkObstacleCollision = function (obstacles) {
	for (var i = 0; i < obstacles.length; i++) {
		var dist = Math.sqrt(Math.pow(bird.x - obstacles[i].x, 2) + Math.pow(bird.y - obstacles[i].y, 2));
		if (dist < 280) {
			LK.setScore(game.score);
			LK.getSound('gameOverJingle').play();
			LK.showGameOver();
		}
	}
};
game.setBackgroundColor(0x660000);
var scoreText = new Text2('0', {
	size: 150,
	fill: '#ff4444',
	font: 'Impact',
	dropShadow: true,
	dropShadowColor: '#990000',
	dropShadowBlur: 5,
	dropShadowDistance: 7,
	dropShadowAngle: 0
});
scoreText.anchor.set(.5, 0);
LK.gui.top.addChild(scoreText);
var scoreText2 = new Text2('0', {
	size: 150,
	fill: '#ffffff',
	font: 'Impact'
});
scoreText2.anchor.set(.5, 0);
scoreText2.x = -4;
scoreText2.y = -5;
LK.gui.top.addChild(scoreText2);
LK.gui.top.addChild(scoreText);
var bird = game.addChild(new Bird());
var leftWall = game.addChild(new Wall());
leftWall.x = 0;
leftWall.y = 1366;
var rightWall = game.addChild(new Wall());
rightWall.x = 2048;
rightWall.y = 1366;
var leftObstacles = [],
	rightObstacles = [];
var obstacleSpawnRandomness = 120;
var obstacleSpawnRandomnessDecrease = 0.025 * (2 / 3);
var obstacleSpawnY = -500;
var leftObstacleSpawnTime = Math.floor(Math.random() * obstacleSpawnRandomness) + obstacleSpawnRandomness;
var rightObstacleSpawnTime = Math.floor(Math.random() * obstacleSpawnRandomness) + obstacleSpawnRandomness;
bird.x = 1024;
bird.y = 1366;
game.isMouseDown = false;
game.down = function (x, y, obj) {
	bird.flap();
	game.isMouseDown = true;
};
game.up = function (x, y, obj) {
	game.isMouseDown = false;
};
game.update = function () {
	// Bird update is now handled automatically by LK engine
	if (game.score > 2) {
		tutorialText.y += 5;
		tutorialTextWhite.y += 5;
	}
	scoreText.setText(game.score);
	scoreText2.setText(game.score);
	game.obstacleSpeed += game.obstacleSpeedIncrease;
	obstacleSpawnRandomness -= obstacleSpawnRandomnessDecrease;
	if (obstacleSpawnRandomness < 20) {
		obstacleSpawnRandomness = 20;
	}
	if (LK.ticks >= leftObstacleSpawnTime) {
		var newObstacle = game.addChildAt(new Obstacle(), 0);
		newObstacle.x = 0;
		newObstacle.y = obstacleSpawnY;
		leftObstacles.push(newObstacle);
		leftObstacleSpawnTime += Math.floor(Math.random() * obstacleSpawnRandomness) + obstacleSpawnRandomness;
	}
	if (LK.ticks >= rightObstacleSpawnTime) {
		var newObstacle = game.addChildAt(new Obstacle(), 0);
		newObstacle.x = 2048;
		newObstacle.y = -newObstacle.height;
		rightObstacles.push(newObstacle);
		rightObstacleSpawnTime += Math.floor(Math.random() * obstacleSpawnRandomness) + obstacleSpawnRandomness;
	}
	if (bird.intersects(leftWall) && bird.xSpeed < 0 || bird.intersects(rightWall) && bird.xSpeed > 0) {
		bird.xSpeed = -bird.xSpeed;
		bird.flip();
		game.score++;
		LK.setScore(game.score);
		LK.getSound('bounce').play();
		tween(bird, {
			tint: 0xff4444
		}, {
			duration: 200,
			onFinish: function onFinish() {
				tween(bird, {
					tint: 0xffffff
				}, {
					duration: 200
				});
			}
		});
	}
	for (var i = leftObstacles.length - 1; i >= 0; i--) {
		// Obstacle movement is now handled automatically by LK engine
		if (leftObstacles[i].y > 3232) {
			leftObstacles[i].destroy();
			leftObstacles.splice(i, 1);
		}
	}
	for (var i = rightObstacles.length - 1; i >= 0; i--) {
		// Obstacle movement is now handled automatically by LK engine
		if (rightObstacles[i].y > 3232) {
			rightObstacles[i].destroy();
			rightObstacles.splice(i, 1);
		}
	}
	game.checkObstacleCollision(leftObstacles);
	game.checkObstacleCollision(rightObstacles);
	if (bird.y < 0 || bird.y > 2732) {
		LK.setScore(game.score);
		LK.getSound('gameOverJingle').play();
		LK.showGameOver();
	}
};

===================================================================
--- original.js
+++ change.js
@@ -1,5 +1,10 @@
 /**** 
+* Plugins
+****/ 
+var tween = LK.import("@upit/tween.v1");
+
+/**** 
 * Classes
 ****/ 
 var Bird = Container.expand(function () {
 	var self = Container.call(this);
@@ -67,9 +72,9 @@
 /**** 
 * Initialize Game
 ****/ 
 var game = new LK.Game({
-	backgroundColor: 0x000000
+	backgroundColor: 0x330000
 });
 
 /**** 
 * Game Code
@@ -85,12 +90,12 @@
 tutorialTextWhite.y = -62;
 LK.gui.bottom.addChild(tutorialTextWhite);
 var tutorialText = new Text2('Tap to Flap\nHold to Float', {
 	size: 150,
-	fill: '#3a84f7',
+	fill: '#ff4444',
 	font: 'Impact',
 	dropShadow: true,
-	dropShadowColor: '#222a9a',
+	dropShadowColor: '#990000',
 	dropShadowBlur: 5,
 	dropShadowDistance: 7,
 	dropShadowAngle: 0,
 	align: 'center'
@@ -110,15 +115,15 @@
 			LK.showGameOver();
 		}
 	}
 };
-game.setBackgroundColor(0xadd8e6);
+game.setBackgroundColor(0x660000);
 var scoreText = new Text2('0', {
 	size: 150,
-	fill: '#3a84f7',
+	fill: '#ff4444',
 	font: 'Impact',
 	dropShadow: true,
-	dropShadowColor: '#222a9a',
+	dropShadowColor: '#990000',
 	dropShadowBlur: 5,
 	dropShadowDistance: 7,
 	dropShadowAngle: 0
 });
@@ -190,8 +195,20 @@
 		bird.flip();
 		game.score++;
 		LK.setScore(game.score);
 		LK.getSound('bounce').play();
+		tween(bird, {
+			tint: 0xff4444
+		}, {
+			duration: 200,
+			onFinish: function onFinish() {
+				tween(bird, {
+					tint: 0xffffff
+				}, {
+					duration: 200
+				});
+			}
+		});
 	}
 	for (var i = leftObstacles.length - 1; i >= 0; i--) {
 		// Obstacle movement is now handled automatically by LK engine
 		if (leftObstacles[i].y > 3232) {