/**** 
* Classes
****/
var ParticleEffect = Container.expand(function (x, y) {
	var self = Container.call(this);
	self.x = x;
	self.y = y;
	var particles = [];
	for (var i = 0; i < 20; i++) {
		var particle = self.attachAsset('star', {
			anchorX: 0.5,
			anchorY: 0.5
		});
		particle.scaleX = particle.scaleY = Math.random() * 0.5 + 0.5;
		particle.alpha = 0.7;
		particle.vx = (Math.random() - 0.5) * 10;
		particle.vy = (Math.random() - 0.5) * 10;
		particles.push(particle);
	}
	self.update = function () {
		for (var i = particles.length - 1; i >= 0; i--) {
			particles[i].x += particles[i].vx;
			particles[i].y += particles[i].vy;
			particles[i].alpha -= 0.02;
			if (particles[i].alpha <= 0) {
				particles[i].destroy();
				particles.splice(i, 1);
			}
		}
		if (particles.length === 0) {
			self.destroy();
		}
	};
	game.addChild(self);
});
var DotParticleEffect = Container.expand(function (x, y) {
	var self = Container.call(this);
	self.x = x;
	self.y = y;
	var particles = [];
	for (var i = 0; i < 30; i++) {
		var particle = self.attachAsset('dot', {
			anchorX: 0.5,
			anchorY: 0.5
		});
		particle.scaleX = particle.scaleY = Math.random() * 0.3 + 0.2;
		particle.alpha = 1;
		particle.vx = (Math.random() - 0.5) * 20;
		particle.vy = (Math.random() - 0.5) * 20;
		particles.push(particle);
	}
	self.update = function () {
		for (var i = particles.length - 1; i >= 0; i--) {
			particles[i].x += particles[i].vx;
			particles[i].y += particles[i].vy;
			particles[i].alpha -= 0.05;
			if (particles[i].alpha <= 0) {
				particles[i].destroy();
				particles.splice(i, 1);
			}
		}
		if (particles.length === 0) {
			self.destroy();
		}
	};
	game.addChild(self);
});
var Dot = Container.expand(function () {
	var self = Container.call(this);
	var dotGraphics = self.attachAsset('dot', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.velocityY = 0;
	self.gravity = 0.5;
	self.bounce = -15;
	self.update = function () {
		var previousY = self.y;
		self.velocityY += self.gravity;
		self.y += self.velocityY;
		if (self.y > 2732 - self.height / 2) {
			self.velocityY = self.bounce;
		}
		self.movedDistance = self.y - previousY;
	};
	self.bounceUp = function () {
		self.velocityY = self.bounce;
	};
});
var Obstacle = Container.expand(function () {
	var self = Container.call(this);
	var obstacleGraphics = self.attachAsset('obstacle', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.direction = Math.random() < 0.5 ? -1 : 1;
	self.speed = (Math.random() * 3 + 5) * self.direction;
	self.rotationSpeed = 0.05;
	self.rotation = 0;
	self.move = function () {
		self.x += self.speed;
		self.rotation += self.rotationSpeed;
		obstacleGraphics.rotation = self.rotation;
		if (self.direction === 1 && self.x > 2048 + self.width / 2 || self.direction === -1 && self.x < -self.width / 2) {
			self.direction *= -1;
			self.speed *= -1;
			self.y = Math.random() * (2732 - self.height) + self.height / 2;
		}
	};
	self.moveDown = function (distance) {
		self.y += distance;
		if (self.y > 2732 - self.height / 2) {
			self.y = -self.height / 2;
		}
	};
});
var Star = Container.expand(function () {
	var self = Container.call(this);
	var starGraphics = self.attachAsset('star', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.moveDown = function (distance) {
		self.y += distance;
		if (self.y > 2732 - self.height / 2) {
			self.y = -self.height / 2;
		}
	};
});

/**** 
* Initialize Game
****/
var game = new LK.Game({
	backgroundColor: 0x000000
});

/**** 
* Game Code
****/
function createParticleEffect(x, y) {
	var effect = new ParticleEffect(x, y);
	LK.on('tick', function () {
		effect.update();
	});
}
function createDotParticleEffect(x, y) {
	var effect = new DotParticleEffect(x, y);
	LK.on('tick', function () {
		effect.update();
	});
}
var dot = game.addChild(new Dot());
dot.x = 2048 / 2;
dot.y = 2732 - dot.height / 2;
var obstacles = [];
for (var i = 0; i < 5; i++) {
	var obstacle = game.addChild(new Obstacle());
	obstacle.x = obstacle.direction === 1 ? -obstacle.width / 2 : 2048 + obstacle.width / 2;
	obstacle.y = Math.random() * (1366 - obstacle.height) + obstacle.height / 2;
	obstacles.push(obstacle);
}
var scoreTxt = new Text2('0', {
	size: 150,
	fill: "#ffffff"
});
scoreTxt.anchor.set(0.5, 0);
scoreTxt.x = 500;
LK.gui.top.addChild(scoreTxt);
LK.gui.top.addChild(scoreTxt);
game.on('down', function (obj) {
	dot.bounceUp();
});
LK.on('tick', function () {
	dot.update();
	for (var i = 0; i < obstacles.length; i++) {
		obstacles[i].move();
		if (dot.y < 1200 && dot.movedDistance < 0) {
			// If the dot moved up and its y position is less than 1400
			obstacles[i].moveDown(-dot.movedDistance);
		}
		if (dot.intersects(obstacles[i])) {
			createDotParticleEffect(dot.x, dot.y);
			dot.destroy();
			LK.setTimeout(function () {
				LK.showGameOver();
			}, 2000);
		}
	}
});
var stars = [];
var star = game.addChild(new Star());
star.x = 2048 / 2;
star.y = 2732 / 2;
stars.push(star);
LK.on('tick', function () {
	dot.update();
	for (var i = 0; i < obstacles.length; i++) {
		obstacles[i].move();
		if (dot.y < 1800 && dot.movedDistance < 0) {
			obstacles[i].moveDown(-dot.movedDistance);
		}
		if (dot.intersects(obstacles[i])) {
			LK.setTimeout(function () {
				LK.showGameOver();
			}, 1000);
		}
	}
	for (var j = stars.length - 1; j >= 0; j--) {
		if (dot.intersects(stars[j])) {
			LK.setScore(LK.getScore() + 1);
			scoreTxt.setText(LK.getScore().toString());
			var oldStarY = stars[j].y;
			createParticleEffect(stars[j].x, stars[j].y);
			stars[j].destroy();
			stars.splice(j, 1);
			var newStar = game.addChild(new Star());
			newStar.x = 2048 / 2;
			newStar.y = oldStarY - 1500;
			stars.push(newStar);
		} else if (dot.y < 1800 && dot.movedDistance < 0) {
			stars[j].moveDown(-dot.movedDistance);
		}
	}
});

===================================================================
--- original.js
+++ change.js
@@ -42,9 +42,9 @@
 		var particle = self.attachAsset('dot', {
 			anchorX: 0.5,
 			anchorY: 0.5
 		});
-		particle.scaleX = particle.scaleY = Math.random() * 0.3 + 0.3;
+		particle.scaleX = particle.scaleY = Math.random() * 0.3 + 0.2;
 		particle.alpha = 1;
 		particle.vx = (Math.random() - 0.5) * 20;
 		particle.vy = (Math.random() - 0.5) * 20;
 		particles.push(particle);