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

/**** 
* Classes
****/ 
var Ball = Container.expand(function (value) {
	var self = Container.call(this);
	self.value = value || 2;
	self.velocityX = 0;
	self.velocityY = 0;
	self.gravity = 0.8;
	self.bounce = 0.4;
	self.friction = 0.98;
	self.radius = 40;
	self.isStatic = false;
	self.mergeTimer = 0;
	self.hasBeenMerged = false;
	var ballAsset = self.attachAsset('ball' + self.value, {
		anchorX: 0.5,
		anchorY: 0.5
	});
	var valueText = new Text2(self.value.toString(), {
		size: 28,
		fill: 0xFFFFFF
	});
	valueText.anchor.set(0.5, 0.5);
	self.addChild(valueText);
	self.update = function () {
		if (self.hasBeenMerged) return;
		if (self.mergeTimer > 0) {
			self.mergeTimer--;
			return;
		}
		if (!self.isStatic) {
			self.velocityY += self.gravity;
			self.x += self.velocityX;
			self.y += self.velocityY;
			// Ground collision (relative to game area)
			var absoluteY = gameArea.y + self.y;
			if (absoluteY + self.radius > gameAreaBottom) {
				self.y = gameAreaBottom - gameArea.y - self.radius;
				self.velocityY *= -self.bounce;
				self.velocityX *= self.friction;
				if (Math.abs(self.velocityY) < 1) {
					self.velocityY = 0;
					self.isStatic = true;
				}
			}
			// Side walls collision (relative to game area)
			var absoluteX = gameArea.x + self.x;
			if (absoluteX - self.radius < gameAreaLeft) {
				self.x = gameAreaLeft - gameArea.x + self.radius;
				self.velocityX *= -self.bounce;
			}
			if (absoluteX + self.radius > gameAreaRight) {
				self.x = gameAreaRight - gameArea.x - self.radius;
				self.velocityX *= -self.bounce;
			}
			// Ball to ball collisions
			for (var i = 0; i < balls.length; i++) {
				var otherBall = balls[i];
				if (otherBall === self || otherBall.hasBeenMerged) continue;
				var dx = otherBall.x - self.x;
				var dy = otherBall.y - self.y;
				var distance = Math.sqrt(dx * dx + dy * dy);
				var minDistance = self.radius + otherBall.radius;
				if (distance < minDistance && distance > 0) {
					// Check for merge
					if (self.value === otherBall.value && self.mergeTimer === 0 && otherBall.mergeTimer === 0) {
						// Merge balls
						var newValue = self.value * 2;
						if (newValue <= 2048) {
							var newBall = new Ball(newValue);
							newBall.x = (self.x + otherBall.x) / 2;
							newBall.y = (self.y + otherBall.y) / 2;
							newBall.velocityX = (self.velocityX + otherBall.velocityX) / 2;
							newBall.velocityY = (self.velocityY + otherBall.velocityY) / 2;
							newBall.mergeTimer = 10;
							balls.push(newBall);
							gameArea.addChild(newBall);
							// Mark for removal
							self.hasBeenMerged = true;
							otherBall.hasBeenMerged = true;
							LK.getSound('merge').play();
							LK.setScore(LK.getScore() + newValue);
							scoreText.setText(LK.getScore());
							// Check win condition
							if (newValue === 2048) {
								LK.showYouWin();
							}
							return;
						}
					}
					// Physical collision
					var overlap = minDistance - distance;
					var separationX = dx / distance * overlap * 0.5;
					var separationY = dy / distance * overlap * 0.5;
					self.x -= separationX;
					self.y -= separationY;
					otherBall.x += separationX;
					otherBall.y += separationY;
					// Velocity exchange
					var relativeVelocityX = self.velocityX - otherBall.velocityX;
					var relativeVelocityY = self.velocityY - otherBall.velocityY;
					var collisionForce = (relativeVelocityX * dx + relativeVelocityY * dy) / (distance * distance);
					self.velocityX -= collisionForce * dx * 0.8;
					self.velocityY -= collisionForce * dy * 0.8;
					otherBall.velocityX += collisionForce * dx * 0.8;
					otherBall.velocityY += collisionForce * dy * 0.8;
					self.velocityX *= self.friction;
					self.velocityY *= self.friction;
					otherBall.velocityX *= otherBall.friction;
					otherBall.velocityY *= otherBall.friction;
				}
			}
		}
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x34495e
});

/**** 
* Game Code
****/ 
var balls = [];
var nextBallValue = 2;
var gameAreaLeft = 224;
var gameAreaRight = 1824;
var gameAreaTop = 400;
var gameAreaBottom = 2600;
var dropCooldown = 0;
var gameAreaHeight = gameAreaBottom - gameAreaTop;
// Create game area background
var gameAreaBg = game.addChild(LK.getAsset('gameArea', {
	anchorX: 0.5,
	anchorY: 0,
	x: 1024,
	y: gameAreaTop
}));
// Create game area container for balls
var gameArea = new Container();
game.addChild(gameArea);
// Create score display
var scoreText = new Text2('0', {
	size: 80,
	fill: 0xFFFFFF
});
scoreText.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreText);
scoreText.y = 100;
// Create next ball preview
var nextBallPreview = LK.getAsset('ball' + nextBallValue, {
	anchorX: 0.5,
	anchorY: 0.5,
	x: 1024,
	y: 300,
	scaleX: 0.75,
	scaleY: 0.75
});
game.addChild(nextBallPreview);
// Create next ball value text
var nextBallText = new Text2(nextBallValue.toString(), {
	size: 24,
	fill: 0xFFFFFF
});
nextBallText.anchor.set(0.5, 0.5);
nextBallText.x = 1024;
nextBallText.y = 300;
game.addChild(nextBallText);
// Create instruction text
var instructionText = new Text2('Tap to drop ball', {
	size: 40,
	fill: 0xFFFFFF
});
instructionText.anchor.set(0.5, 0);
instructionText.x = 1024;
instructionText.y = 150;
game.addChild(instructionText);
function getRandomNextBallValue() {
	var values = [2, 4, 8];
	return values[Math.floor(Math.random() * values.length)];
}
function updateNextBallPreview() {
	game.removeChild(nextBallPreview);
	game.removeChild(nextBallText);
	nextBallPreview = LK.getAsset('ball' + nextBallValue, {
		anchorX: 0.5,
		anchorY: 0.5,
		x: 1024,
		y: 300,
		scaleX: 0.75,
		scaleY: 0.75
	});
	game.addChild(nextBallPreview);
	nextBallText = new Text2(nextBallValue.toString(), {
		size: 24,
		fill: 0xFFFFFF
	});
	nextBallText.anchor.set(0.5, 0.5);
	nextBallText.x = 1024;
	nextBallText.y = 300;
	game.addChild(nextBallText);
}
function checkGameOver() {
	for (var i = 0; i < balls.length; i++) {
		var absoluteY = gameArea.y + balls[i].y;
		if (absoluteY - balls[i].radius < gameAreaTop + 100) {
			LK.showGameOver();
			return;
		}
	}
}
function cleanupMergedBalls() {
	for (var i = balls.length - 1; i >= 0; i--) {
		if (balls[i].hasBeenMerged) {
			gameArea.removeChild(balls[i]);
			balls[i].destroy();
			balls.splice(i, 1);
		}
	}
}
game.down = function (x, y, obj) {
	if (dropCooldown > 0) return;
	// Constrain drop position to game area (convert to local coordinates)
	var dropX = Math.max(gameAreaLeft + 40, Math.min(gameAreaRight - 40, x)) - gameArea.x;
	var newBall = new Ball(nextBallValue);
	newBall.x = dropX;
	newBall.y = 50; // Start just below the top of game area
	newBall.velocityX = 0;
	newBall.velocityY = 0;
	balls.push(newBall);
	gameArea.addChild(newBall);
	LK.getSound('drop').play();
	// Update next ball
	nextBallValue = getRandomNextBallValue();
	updateNextBallPreview();
	dropCooldown = 30; // 0.5 seconds at 60fps
};
game.update = function () {
	if (dropCooldown > 0) {
		dropCooldown--;
	}
	cleanupMergedBalls();
	checkGameOver();
	// Update score display
	scoreText.setText(LK.getScore());
};

===================================================================
--- original.js
+++ change.js
@@ -37,25 +37,27 @@
 		if (!self.isStatic) {
 			self.velocityY += self.gravity;
 			self.x += self.velocityX;
 			self.y += self.velocityY;
-			// Ground collision
-			if (self.y + self.radius > gameAreaBottom) {
-				self.y = gameAreaBottom - self.radius;
+			// Ground collision (relative to game area)
+			var absoluteY = gameArea.y + self.y;
+			if (absoluteY + self.radius > gameAreaBottom) {
+				self.y = gameAreaBottom - gameArea.y - self.radius;
 				self.velocityY *= -self.bounce;
 				self.velocityX *= self.friction;
 				if (Math.abs(self.velocityY) < 1) {
 					self.velocityY = 0;
 					self.isStatic = true;
 				}
 			}
-			// Side walls collision
-			if (self.x - self.radius < gameAreaLeft) {
-				self.x = gameAreaLeft + self.radius;
+			// Side walls collision (relative to game area)
+			var absoluteX = gameArea.x + self.x;
+			if (absoluteX - self.radius < gameAreaLeft) {
+				self.x = gameAreaLeft - gameArea.x + self.radius;
 				self.velocityX *= -self.bounce;
 			}
-			if (self.x + self.radius > gameAreaRight) {
-				self.x = gameAreaRight - self.radius;
+			if (absoluteX + self.radius > gameAreaRight) {
+				self.x = gameAreaRight - gameArea.x - self.radius;
 				self.velocityX *= -self.bounce;
 			}
 			// Ball to ball collisions
 			for (var i = 0; i < balls.length; i++) {
@@ -137,14 +139,17 @@
 var gameAreaBottom = 2600;
 var dropCooldown = 0;
 var gameAreaHeight = gameAreaBottom - gameAreaTop;
 // Create game area background
-var gameArea = game.addChild(LK.getAsset('gameArea', {
+var gameAreaBg = game.addChild(LK.getAsset('gameArea', {
 	anchorX: 0.5,
 	anchorY: 0,
 	x: 1024,
 	y: gameAreaTop
 }));
+// Create game area container for balls
+var gameArea = new Container();
+game.addChild(gameArea);
 // Create score display
 var scoreText = new Text2('0', {
 	size: 80,
 	fill: 0xFFFFFF
@@ -206,29 +211,31 @@
 	game.addChild(nextBallText);
 }
 function checkGameOver() {
 	for (var i = 0; i < balls.length; i++) {
-		if (balls[i].y - balls[i].radius < gameAreaTop + 100) {
+		var absoluteY = gameArea.y + balls[i].y;
+		if (absoluteY - balls[i].radius < gameAreaTop + 100) {
 			LK.showGameOver();
 			return;
 		}
 	}
 }
 function cleanupMergedBalls() {
 	for (var i = balls.length - 1; i >= 0; i--) {
 		if (balls[i].hasBeenMerged) {
+			gameArea.removeChild(balls[i]);
 			balls[i].destroy();
 			balls.splice(i, 1);
 		}
 	}
 }
 game.down = function (x, y, obj) {
 	if (dropCooldown > 0) return;
-	// Constrain drop position to game area
-	var dropX = Math.max(gameAreaLeft + 40, Math.min(gameAreaRight - 40, x));
+	// Constrain drop position to game area (convert to local coordinates)
+	var dropX = Math.max(gameAreaLeft + 40, Math.min(gameAreaRight - 40, x)) - gameArea.x;
 	var newBall = new Ball(nextBallValue);
 	newBall.x = dropX;
-	newBall.y = gameAreaTop + 50;
+	newBall.y = 50; // Start just below the top of game area
 	newBall.velocityX = 0;
 	newBall.velocityY = 0;
 	balls.push(newBall);
 	gameArea.addChild(newBall);