===================================================================
--- original.js
+++ change.js
@@ -1,6 +1,201 @@
-/****
+/**** 
+* Plugins
+****/ 
+var tween = LK.import("@upit/tween.v1");
+
+/**** 
+* Classes
+****/ 
+// Block obstacle
+var Block = Container.expand(function () {
+	var self = Container.call(this);
+	var blockGfx = self.attachAsset('block', {
+		anchorX: 0.5,
+		anchorY: 1
+	});
+	self.width = blockGfx.width;
+	self.height = blockGfx.height;
+	self.type = 'block';
+	self.update = function () {
+		self.x -= obstacleSpeed;
+	};
+	return self;
+});
+// Player Cube
+var Cube = Container.expand(function () {
+	var self = Container.call(this);
+	var cubeGfx = self.attachAsset('cube', {
+		anchorX: 0.5,
+		anchorY: 1
+	});
+	self.width = cubeGfx.width;
+	self.height = cubeGfx.height;
+	self.velY = 0;
+	self.isOnGround = false;
+	// Jump method
+	self.jump = function () {
+		if (self.isOnGround) {
+			self.velY = -48; // Jump velocity
+			self.isOnGround = false;
+		}
+	};
+	// Update method
+	self.update = function () {
+		// Gravity
+		self.velY += 4.2;
+		if (self.velY > 60) self.velY = 60;
+		self.y += self.velY;
+		// Prevent falling below ground
+		if (self.y > groundY) {
+			self.y = groundY;
+			self.velY = 0;
+			self.isOnGround = true;
+		}
+	};
+	return self;
+});
+// Spike obstacle
+var Spike = Container.expand(function () {
+	var self = Container.call(this);
+	var spikeGfx = self.attachAsset('spike', {
+		anchorX: 0.5,
+		anchorY: 1
+	});
+	self.width = spikeGfx.width;
+	self.height = spikeGfx.height;
+	self.type = 'spike';
+	self.update = function () {
+		self.x -= obstacleSpeed;
+	};
+	return self;
+});
+
+/**** 
 * Initialize Game
-****/
+****/ 
 var game = new LK.Game({
-	backgroundColor: 0x000000
-});
\ No newline at end of file
+	backgroundColor: 0xf0f0f0
+});
+
+/**** 
+* Game Code
+****/ 
+// Block obstacle
+// Spike obstacle
+// Ground
+// Cube player
+// Constants
+var groundHeight = 80;
+var groundY = 2732 - groundHeight;
+var startX = 400;
+var startY = groundY;
+var obstacleSpeed = 24;
+var minObstacleGap = 420;
+var maxObstacleGap = 700;
+var lastObstacleX = 0;
+var score = 0;
+var gameStarted = false;
+// Arrays
+var obstacles = [];
+// Add ground
+var ground = LK.getAsset('ground', {
+	anchorX: 0,
+	anchorY: 0
+});
+ground.x = 0;
+ground.y = groundY;
+game.addChild(ground);
+// Add player cube
+var cube = new Cube();
+cube.x = startX;
+cube.y = startY;
+game.addChild(cube);
+// Score text
+var scoreTxt = new Text2('0', {
+	size: 120,
+	fill: 0x222222
+});
+scoreTxt.anchor.set(0.5, 0);
+LK.gui.top.addChild(scoreTxt);
+// Helper: spawn obstacle
+function spawnObstacle() {
+	// Randomly choose spike or block
+	var type = Math.random() < 0.6 ? 'spike' : 'block';
+	var obs;
+	if (type === 'spike') {
+		obs = new Spike();
+		obs.x = 2048 + 100;
+		obs.y = groundY;
+	} else {
+		obs = new Block();
+		obs.x = 2048 + 100;
+		obs.y = groundY;
+	}
+	obstacles.push(obs);
+	game.addChild(obs);
+	lastObstacleX = obs.x;
+}
+// Helper: reset game state
+function resetGame() {
+	// Remove obstacles
+	for (var i = 0; i < obstacles.length; ++i) {
+		obstacles[i].destroy();
+	}
+	obstacles.length = 0;
+	cube.x = startX;
+	cube.y = startY;
+	cube.velY = 0;
+	cube.isOnGround = true;
+	lastObstacleX = 1200;
+	score = 0;
+	scoreTxt.setText(score);
+	gameStarted = false;
+}
+// Start game on first tap
+game.down = function (x, y, obj) {
+	if (!gameStarted) {
+		gameStarted = true;
+		return;
+	}
+	cube.jump();
+};
+// Main update loop
+game.update = function () {
+	if (!gameStarted) return;
+	// Update player
+	cube.update();
+	// Update obstacles
+	for (var i = obstacles.length - 1; i >= 0; --i) {
+		var obs = obstacles[i];
+		obs.update();
+		// Remove if off screen
+		if (obs.x < -200) {
+			obs.destroy();
+			obstacles.splice(i, 1);
+			continue;
+		}
+		// Collision detection
+		if (cube.intersects(obs)) {
+			// Flash screen and game over
+			LK.effects.flashScreen(0xff0000, 800);
+			LK.showGameOver();
+			return;
+		}
+		// Score: passed obstacle
+		if (!obs.passed && obs.x + obs.width / 2 < cube.x - cube.width / 2) {
+			obs.passed = true;
+			score += 1;
+			scoreTxt.setText(score);
+		}
+	}
+	// Spawn new obstacles
+	if (obstacles.length === 0 || 2048 - lastObstacleX > minObstacleGap + Math.random() * (maxObstacleGap - minObstacleGap)) {
+		spawnObstacle();
+	}
+};
+// Reset game on game over
+LK.on('gameover', function () {
+	resetGame();
+});
+// Initial state
+resetGame();
\ No newline at end of file