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

/**** 
* Classes
****/ 
// Hamster (player) class
var Hamster = Container.expand(function () {
	var self = Container.call(this);
	var hamsterSprite = self.attachAsset('hamster', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.radius = hamsterSprite.width * 0.5;
	// For collision, use self.x, self.y, self.radius
	// No per-instance update needed; movement is handled by drag
	return self;
});

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

/**** 
* Game Code
****/ 
// Game constants
var GAME_WIDTH = 2048;
var GAME_HEIGHT = 2732;
var HAMSTER_START_X = GAME_WIDTH / 2;
var HAMSTER_START_Y = GAME_HEIGHT - 500;
// Camera state
var cameraOffsetX = 0;
var cameraOffsetY = 0;
// Game state
var hamster = null;
var dragNode = null;
// --- Infinite grass background ---
var bgGrass1 = LK.getAsset('grass', {
	anchorX: 0,
	anchorY: 0,
	width: GAME_WIDTH,
	height: GAME_HEIGHT
});
var bgGrass2 = LK.getAsset('grass', {
	anchorX: 0,
	anchorY: 0,
	width: GAME_WIDTH,
	height: GAME_HEIGHT
});
bgGrass1.y = 0;
bgGrass2.y = -GAME_HEIGHT;
game.addChild(bgGrass1);
game.addChild(bgGrass2);
// --- Hamster ---
// Allow dragging hamster from anywhere on the screen
hamster = new Hamster();
hamster.x = HAMSTER_START_X;
hamster.y = HAMSTER_START_Y;
game.addChild(hamster);
game.down = function (x, y, obj) {
	dragNode = hamster;
};
game.up = function (x, y, obj) {
	dragNode = null;
};
game.move = function (x, y, obj) {
	if (dragNode) {
		// Convert screen drag to world position by adding camera offset
		var nx = x + cameraOffsetX;
		var ny = y + cameraOffsetY;
		var r = hamster.radius;
		if (nx < r) nx = r;
		if (nx > GAME_WIDTH - r) nx = GAME_WIDTH - r;
		if (ny < r + 100) ny = r + 100; // Don't allow top 100px (menu)
		if (ny > GAME_HEIGHT - r) ny = GAME_HEIGHT - r;
		hamster.x = nx;
		hamster.y = ny;
	}
};
// --- Game update ---
game.update = function () {
	// Camera follows hamster: center hamster on screen
	cameraOffsetX = hamster.x - GAME_WIDTH / 2;
	cameraOffsetY = hamster.y - GAME_HEIGHT / 2;
	// Clamp camera to game bounds (optional, if you want to restrict camera movement)
	if (cameraOffsetX < 0) cameraOffsetX = 0;
	if (cameraOffsetY < 0) cameraOffsetY = 0;
	if (cameraOffsetX > GAME_WIDTH) cameraOffsetX = GAME_WIDTH;
	if (cameraOffsetY > GAME_HEIGHT) cameraOffsetY = GAME_HEIGHT;
	// Scroll background grass with camera
	var speed = 8;
	bgGrass1.y += speed;
	bgGrass2.y += speed;
	// Apply camera offset to backgrounds
	bgGrass1.x = -cameraOffsetX;
	bgGrass1.y = -cameraOffsetY % GAME_HEIGHT;
	bgGrass2.x = -cameraOffsetX;
	bgGrass2.y = -cameraOffsetY % GAME_HEIGHT - GAME_HEIGHT;
	// Apply camera offset to hamster
	hamster.x = HAMSTER_START_X;
	hamster.y = HAMSTER_START_Y;
	// Loop grass backgrounds
	if (bgGrass1.y >= GAME_HEIGHT) {
		bgGrass1.y = bgGrass2.y - GAME_HEIGHT;
	}
	if (bgGrass2.y >= GAME_HEIGHT) {
		bgGrass2.y = bgGrass1.y - GAME_HEIGHT;
	}
};

===================================================================
--- original.js
+++ change.js
@@ -33,8 +33,11 @@
 var GAME_WIDTH = 2048;
 var GAME_HEIGHT = 2732;
 var HAMSTER_START_X = GAME_WIDTH / 2;
 var HAMSTER_START_Y = GAME_HEIGHT - 500;
+// Camera state
+var cameraOffsetX = 0;
+var cameraOffsetY = 0;
 // Game state
 var hamster = null;
 var dragNode = null;
 // --- Infinite grass background ---
@@ -67,11 +70,11 @@
 	dragNode = null;
 };
 game.move = function (x, y, obj) {
 	if (dragNode) {
-		// Clamp hamster to game area
-		var nx = x;
-		var ny = y;
+		// Convert screen drag to world position by adding camera offset
+		var nx = x + cameraOffsetX;
+		var ny = y + cameraOffsetY;
 		var r = hamster.radius;
 		if (nx < r) nx = r;
 		if (nx > GAME_WIDTH - r) nx = GAME_WIDTH - r;
 		if (ny < r + 100) ny = r + 100; // Don't allow top 100px (menu)
@@ -81,12 +84,28 @@
 	}
 };
 // --- Game update ---
 game.update = function () {
-	// Scroll background grass
+	// Camera follows hamster: center hamster on screen
+	cameraOffsetX = hamster.x - GAME_WIDTH / 2;
+	cameraOffsetY = hamster.y - GAME_HEIGHT / 2;
+	// Clamp camera to game bounds (optional, if you want to restrict camera movement)
+	if (cameraOffsetX < 0) cameraOffsetX = 0;
+	if (cameraOffsetY < 0) cameraOffsetY = 0;
+	if (cameraOffsetX > GAME_WIDTH) cameraOffsetX = GAME_WIDTH;
+	if (cameraOffsetY > GAME_HEIGHT) cameraOffsetY = GAME_HEIGHT;
+	// Scroll background grass with camera
 	var speed = 8;
 	bgGrass1.y += speed;
 	bgGrass2.y += speed;
+	// Apply camera offset to backgrounds
+	bgGrass1.x = -cameraOffsetX;
+	bgGrass1.y = -cameraOffsetY % GAME_HEIGHT;
+	bgGrass2.x = -cameraOffsetX;
+	bgGrass2.y = -cameraOffsetY % GAME_HEIGHT - GAME_HEIGHT;
+	// Apply camera offset to hamster
+	hamster.x = HAMSTER_START_X;
+	hamster.y = HAMSTER_START_Y;
 	// Loop grass backgrounds
 	if (bgGrass1.y >= GAME_HEIGHT) {
 		bgGrass1.y = bgGrass2.y - GAME_HEIGHT;
 	}