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

/**** 
* Classes
****/ 
var Coin = Container.expand(function () {
	var self = Container.call(this);
	var coinGraphics = self.attachAsset('coin', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = gameSpeed;
	self.collected = false;
	self.update = function () {
		self.y += self.speed;
		coinGraphics.rotation += 0.1;
	};
	return self;
});
var Obstacle = Container.expand(function () {
	var self = Container.call(this);
	var obstacleGraphics = self.attachAsset('obstacle', {
		anchorX: 0.5,
		anchorY: 1.0
	});
	self.speed = gameSpeed;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
var Player = Container.expand(function () {
	var self = Container.call(this);
	var playerGraphics = self.attachAsset('player', {
		anchorX: 0.5,
		anchorY: 1.0
	});
	self.lane = 1; // 0=left, 1=center, 2=right
	self.isJumping = false;
	self.isSliding = false;
	self.jumpStartY = 0;
	self.slideTimer = 0;
	self.update = function () {
		// Handle jumping
		if (self.isJumping) {
			var jumpProgress = (LK.ticks - self.jumpStartTick) / 45; // Slower jump duration for longer air time
			if (jumpProgress >= 1) {
				self.isJumping = false;
				self.y = self.jumpStartY;
			} else {
				var jumpHeight = Math.sin(jumpProgress * Math.PI) * 400;
				self.y = self.jumpStartY - jumpHeight;
			}
		}
		// Handle sliding
		if (self.isSliding) {
			self.slideTimer--;
			if (self.slideTimer <= 0) {
				self.isSliding = false;
				playerGraphics.scaleY = 1.0;
			}
		}
		// Update lane position
		var targetX = 512 + self.lane * 512;
		self.x += (targetX - self.x) * 0.2;
	};
	self.jump = function () {
		if (!self.isJumping && !self.isSliding) {
			self.isJumping = true;
			self.jumpStartY = self.y;
			self.jumpStartTick = LK.ticks;
			LK.getSound('jump').play();
			// Add tween for smoother jump animation
			tween(self, {
				scaleX: 1.2,
				scaleY: 0.8
			}, {
				duration: 150,
				easing: tween.easeOut,
				onFinish: function onFinish() {
					tween(self, {
						scaleX: 1.0,
						scaleY: 1.0
					}, {
						duration: 600,
						easing: tween.easeOut // Slower landing for gravity effect
					});
				}
			});
		}
	};
	self.slide = function () {
		if (!self.isJumping && !self.isSliding) {
			self.isSliding = true;
			self.slideTimer = 30;
			playerGraphics.scaleY = 0.5;
		}
	};
	self.moveLeft = function () {
		if (self.lane > 0) {
			self.lane--;
		}
	};
	self.moveRight = function () {
		if (self.lane < 2) {
			self.lane++;
		}
	};
	self.isHighEnoughToClear = function () {
		if (!self.isJumping) return false;
		var jumpProgress = (LK.ticks - self.jumpStartTick) / 45; // Match slower gravity timing
		var jumpHeight = Math.sin(jumpProgress * Math.PI) * 400;
		return jumpHeight > 120; // Player needs to be at least 120 pixels high to clear obstacles
	};
	return self;
});
var Track = Container.expand(function () {
	var self = Container.call(this);
	var trackGraphics = self.attachAsset('track', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = gameSpeed;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
var Train = Container.expand(function () {
	var self = Container.call(this);
	var trainGraphics = self.attachAsset('train', {
		anchorX: 0.5,
		anchorY: 1.0
	});
	self.speed = gameSpeed;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});

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

/**** 
* Game Code
****/ 
var gameSpeed = 8;
var difficulty = 'medium';
var obstacleSpawnRate = 120;
var coinSpawnRate = 60;
var distance = 0;
var coins = 0;
var player;
var obstacles = [];
var trains = [];
var coinsList = [];
var tracks = [];
var lastSwipeX = 0;
var lastSwipeY = 0;
var swipeStartX = 0;
var swipeStartY = 0;
var isSwipeStarted = false;
// Initialize tracks for visual effect
for (var i = 0; i < 5; i++) {
	var track = new Track();
	track.x = 1024;
	track.y = i * 200 - 200;
	tracks.push(track);
	game.addChild(track);
}
// Initialize player
player = new Player();
player.x = 1024;
player.y = 2200;
game.addChild(player);
// UI Elements
var scoreText = new Text2('Score: 0', {
	size: 60,
	fill: 0xFFFFFF
});
scoreText.anchor.set(0, 0);
scoreText.x = 120;
scoreText.y = 50;
LK.gui.addChild(scoreText);
var coinsText = new Text2('Coins: 0', {
	size: 60,
	fill: 0xFFD700
});
coinsText.anchor.set(1, 0);
coinsText.x = LK.gui.width - 50;
coinsText.y = 50;
LK.gui.addChild(coinsText);
var distanceText = new Text2('Distance: 0m', {
	size: 50,
	fill: 0xFFFFFF
});
distanceText.anchor.set(0.5, 0);
distanceText.x = LK.gui.width / 2;
distanceText.y = 50;
LK.gui.addChild(distanceText);
// Set difficulty based on game design
function setDifficulty(diff) {
	difficulty = diff;
	switch (diff) {
		case 'easy':
			gameSpeed = 6;
			obstacleSpawnRate = 150;
			coinSpawnRate = 45;
			break;
		case 'medium':
			gameSpeed = 8;
			obstacleSpawnRate = 120;
			coinSpawnRate = 60;
			break;
		case 'hard':
			gameSpeed = 12;
			obstacleSpawnRate = 90;
			coinSpawnRate = 80;
			break;
	}
}
// Set default difficulty
setDifficulty('medium');
// Handle swipe controls
game.down = function (x, y, obj) {
	// Only handle swipes during gameplay
	if (gameState !== 'playing') {
		return;
	}
	swipeStartX = x;
	swipeStartY = y;
	isSwipeStarted = true;
};
game.up = function (x, y, obj) {
	// Only handle swipes during gameplay
	if (gameState !== 'playing') {
		return;
	}
	if (!isSwipeStarted) return;
	var deltaX = x - swipeStartX;
	var deltaY = y - swipeStartY;
	var swipeThreshold = 50;
	if (Math.abs(deltaX) > Math.abs(deltaY)) {
		// Horizontal swipe
		if (Math.abs(deltaX) > swipeThreshold) {
			if (deltaX > 0) {
				player.moveRight();
			} else {
				player.moveLeft();
			}
		}
	} else {
		// Vertical swipe
		if (Math.abs(deltaY) > swipeThreshold) {
			if (deltaY < 0) {
				player.jump();
			} else {
				player.slide();
			}
		}
	}
	isSwipeStarted = false;
};
// Spawn obstacles
function spawnObstacle() {
	var availableLanes = [0, 1, 2];
	// Remove lanes that already have obstacles in extended spawn area
	for (var i = obstacles.length - 1; i >= 0; i--) {
		var obstacle = obstacles[i];
		if (obstacle.y >= -600 && obstacle.y <= 400) {
			// Obstacle in extended spawn area
			var obstacleLaneIndex = availableLanes.indexOf(obstacle.lane);
			if (obstacleLaneIndex > -1) {
				availableLanes.splice(obstacleLaneIndex, 1);
			}
		}
	}
	// Remove lanes that already have trains in extended spawn area
	for (var i = trains.length - 1; i >= 0; i--) {
		var train = trains[i];
		if (train.y >= -600 && train.y <= 400) {
			// Train in extended spawn area
			var trainLaneIndex = availableLanes.indexOf(train.lane);
			if (trainLaneIndex > -1) {
				availableLanes.splice(trainLaneIndex, 1);
			}
		}
	}
	// Remove lanes that have coins in spawn area to prevent overlap
	for (var i = coinsList.length - 1; i >= 0; i--) {
		var coin = coinsList[i];
		if (coin.y >= -400 && coin.y <= 200) {
			// Coin in spawn area
			var coinLaneIndex = availableLanes.indexOf(coin.lane);
			if (coinLaneIndex > -1) {
				availableLanes.splice(coinLaneIndex, 1);
			}
		}
	}
	// If no lanes available, don't spawn obstacle
	if (availableLanes.length === 0) {
		return;
	}
	var lane = availableLanes[Math.floor(Math.random() * availableLanes.length)];
	var obstacleType = Math.random();
	if (obstacleType < 0.6) {
		// Regular obstacle
		var obstacle = new Obstacle();
		obstacle.x = 512 + lane * 512;
		obstacle.y = -100;
		obstacle.lane = lane;
		obstacles.push(obstacle);
		game.addChild(obstacle);
	} else {
		// Train
		var train = new Train();
		train.x = 512 + lane * 512;
		train.y = -150;
		train.lane = lane;
		trains.push(train);
		game.addChild(train);
	}
}
// Spawn coins
function spawnCoin() {
	var availableLanes = [0, 1, 2];
	// Remove lanes that have trains in spawn area
	for (var i = trains.length - 1; i >= 0; i--) {
		var train = trains[i];
		if (train.y >= -600 && train.y <= 200) {
			// Train in spawn area
			var trainLaneIndex = availableLanes.indexOf(train.lane);
			if (trainLaneIndex > -1) {
				availableLanes.splice(trainLaneIndex, 1);
			}
		}
	}
	// Remove lanes that have obstacles in spawn area
	for (var i = obstacles.length - 1; i >= 0; i--) {
		var obstacle = obstacles[i];
		if (obstacle.y >= -400 && obstacle.y <= 200) {
			// Obstacle in spawn area
			var obstacleLaneIndex = availableLanes.indexOf(obstacle.lane);
			if (obstacleLaneIndex > -1) {
				availableLanes.splice(obstacleLaneIndex, 1);
			}
		}
	}
	// Remove lanes that already have coins in spawn area
	for (var i = coinsList.length - 1; i >= 0; i--) {
		var coin = coinsList[i];
		if (coin.y >= -400 && coin.y <= 200) {
			// Coin in spawn area
			var coinLaneIndex = availableLanes.indexOf(coin.lane);
			if (coinLaneIndex > -1) {
				availableLanes.splice(coinLaneIndex, 1);
			}
		}
	}
	// If no lanes available, don't spawn coin
	if (availableLanes.length === 0) {
		return;
	}
	var lane = availableLanes[Math.floor(Math.random() * availableLanes.length)];
	var coin = new Coin();
	coin.x = 512 + lane * 512;
	coin.y = -50;
	coin.lane = lane;
	coinsList.push(coin);
	game.addChild(coin);
}
// Check collisions
function checkCollisions() {
	// Check obstacle collisions
	for (var i = obstacles.length - 1; i >= 0; i--) {
		var obstacle = obstacles[i];
		if (obstacle.lane === player.lane) {
			if (Math.abs(obstacle.y - player.y) < 80) {
				// Check if player can clear obstacle by jumping
				if (!player.isJumping || !player.isHighEnoughToClear()) {
					// Collision detected
					LK.showGameOver();
					return;
				}
			}
		}
	}
	// Check train collisions
	for (var i = trains.length - 1; i >= 0; i--) {
		var train = trains[i];
		if (train.lane === player.lane) {
			if (Math.abs(train.y - player.y) < 90) {
				// Check if player can clear train by jumping
				if (!player.isJumping || !player.isHighEnoughToClear()) {
					// Collision detected
					LK.showGameOver();
					return;
				}
			}
		}
	}
	// Check coin collection
	for (var i = coinsList.length - 1; i >= 0; i--) {
		var coin = coinsList[i];
		if (!coin.collected && coin.lane === player.lane) {
			if (Math.abs(coin.y - player.y) < 60) {
				coin.collected = true;
				coins++;
				LK.setScore(LK.getScore() + 10);
				LK.getSound('collect').play();
				coin.destroy();
				coinsList.splice(i, 1);
			}
		}
	}
}
// Clean up off-screen objects
function cleanupObjects() {
	// Clean obstacles
	for (var i = obstacles.length - 1; i >= 0; i--) {
		if (obstacles[i].y > 2800) {
			obstacles[i].destroy();
			obstacles.splice(i, 1);
		}
	}
	// Clean trains
	for (var i = trains.length - 1; i >= 0; i--) {
		if (trains[i].y > 2800) {
			trains[i].destroy();
			trains.splice(i, 1);
		}
	}
	// Clean coins
	for (var i = coinsList.length - 1; i >= 0; i--) {
		if (coinsList[i].y > 2800) {
			coinsList[i].destroy();
			coinsList.splice(i, 1);
		}
	}
	// Reset tracks
	for (var i = 0; i < tracks.length; i++) {
		if (tracks[i].y > 2800) {
			tracks[i].y = -200;
		}
	}
}
// Update UI
function updateUI() {
	distance = Math.floor(LK.ticks / 6);
	scoreText.setText('Score: ' + LK.getScore());
	coinsText.setText('Coins: ' + coins);
	distanceText.setText('Distance: ' + distance + 'm');
}
// Main game update
game.update = function () {
	// Only update game when in playing state
	if (gameState !== 'playing') {
		return;
	}
	// Update speed over time
	gameSpeed = Math.min(15, 8 + LK.ticks / 1800);
	// Spawn obstacles
	if (LK.ticks % obstacleSpawnRate === 0) {
		spawnObstacle();
	}
	// Spawn coins
	if (LK.ticks % coinSpawnRate === 0) {
		spawnCoin();
	}
	// Update score based on distance
	if (LK.ticks % 6 === 0) {
		LK.setScore(LK.getScore() + 1);
	}
	// Check collisions
	checkCollisions();
	// Clean up objects
	cleanupObjects();
	// Update UI
	updateUI();
};
// Game state management
var gameState = 'intro'; // 'intro', 'playing'
var introScreen;
var introTitle;
var introInstructions;
var startButton;
// Create intro screen
function createIntroScreen() {
	introScreen = new Container();
	// Background overlay
	var overlay = LK.getAsset('barrier', {
		anchorX: 0.5,
		anchorY: 0.5,
		scaleX: 6,
		scaleY: 15,
		tint: 0x000000,
		alpha: 0.8
	});
	overlay.x = 1024;
	overlay.y = 1366;
	introScreen.addChild(overlay);
	// Title
	introTitle = new Text2('ENDLESS RUNNER', {
		size: 120,
		fill: 0xFFD700
	});
	introTitle.anchor.set(0.5, 0.5);
	introTitle.x = 1024;
	introTitle.y = 800;
	introScreen.addChild(introTitle);
	// Instructions
	var instructions = ['SWIPE LEFT/RIGHT - Change lanes', 'SWIPE UP - Jump over obstacles', 'SWIPE DOWN - Slide under barriers', '', 'Collect coins and avoid obstacles!', 'Jump high enough to clear trains!'];
	for (var i = 0; i < instructions.length; i++) {
		var instructionText = new Text2(instructions[i], {
			size: 60,
			fill: 0xFFFFFF
		});
		instructionText.anchor.set(0.5, 0.5);
		instructionText.x = 1024;
		instructionText.y = 1100 + i * 80;
		introScreen.addChild(instructionText);
	}
	// Start button
	var buttonBg = LK.getAsset('barrier', {
		anchorX: 0.5,
		anchorY: 0.5,
		scaleX: 1.5,
		scaleY: 0.8,
		tint: 0x00AA00
	});
	buttonBg.x = 1024;
	buttonBg.y = 1800;
	var buttonText = new Text2('TAP TO START', {
		size: 80,
		fill: 0xFFFFFF
	});
	buttonText.anchor.set(0.5, 0.5);
	buttonText.x = 1024;
	buttonText.y = 1800;
	startButton = new Container();
	startButton.addChild(buttonBg);
	startButton.addChild(buttonText);
	startButton.x = 0;
	startButton.y = 0;
	// Add button interaction
	startButton.down = function (x, y, obj) {
		startGame();
	};
	introScreen.addChild(startButton);
	game.addChild(introScreen);
}
// Start the actual game
function startGame() {
	gameState = 'playing';
	if (introScreen) {
		introScreen.destroy();
	}
	// Start background music
	LK.playMusic('bgmusic');
}
// Show intro screen at start
createIntroScreen();

===================================================================
--- original.js
+++ change.js
@@ -230,13 +230,21 @@
 // Set default difficulty
 setDifficulty('medium');
 // Handle swipe controls
 game.down = function (x, y, obj) {
+	// Only handle swipes during gameplay
+	if (gameState !== 'playing') {
+		return;
+	}
 	swipeStartX = x;
 	swipeStartY = y;
 	isSwipeStarted = true;
 };
 game.up = function (x, y, obj) {
+	// Only handle swipes during gameplay
+	if (gameState !== 'playing') {
+		return;
+	}
 	if (!isSwipeStarted) return;
 	var deltaX = x - swipeStartX;
 	var deltaY = y - swipeStartY;
 	var swipeThreshold = 50;
@@ -452,8 +460,12 @@
 	distanceText.setText('Distance: ' + distance + 'm');
 }
 // Main game update
 game.update = function () {
+	// Only update game when in playing state
+	if (gameState !== 'playing') {
+		return;
+	}
 	// Update speed over time
 	gameSpeed = Math.min(15, 8 + LK.ticks / 1800);
 	// Spawn obstacles
 	if (LK.ticks % obstacleSpawnRate === 0) {
@@ -473,6 +485,86 @@
 	cleanupObjects();
 	// Update UI
 	updateUI();
 };
-// Start background music
-LK.playMusic('bgmusic');
\ No newline at end of file
+// Game state management
+var gameState = 'intro'; // 'intro', 'playing'
+var introScreen;
+var introTitle;
+var introInstructions;
+var startButton;
+// Create intro screen
+function createIntroScreen() {
+	introScreen = new Container();
+	// Background overlay
+	var overlay = LK.getAsset('barrier', {
+		anchorX: 0.5,
+		anchorY: 0.5,
+		scaleX: 6,
+		scaleY: 15,
+		tint: 0x000000,
+		alpha: 0.8
+	});
+	overlay.x = 1024;
+	overlay.y = 1366;
+	introScreen.addChild(overlay);
+	// Title
+	introTitle = new Text2('ENDLESS RUNNER', {
+		size: 120,
+		fill: 0xFFD700
+	});
+	introTitle.anchor.set(0.5, 0.5);
+	introTitle.x = 1024;
+	introTitle.y = 800;
+	introScreen.addChild(introTitle);
+	// Instructions
+	var instructions = ['SWIPE LEFT/RIGHT - Change lanes', 'SWIPE UP - Jump over obstacles', 'SWIPE DOWN - Slide under barriers', '', 'Collect coins and avoid obstacles!', 'Jump high enough to clear trains!'];
+	for (var i = 0; i < instructions.length; i++) {
+		var instructionText = new Text2(instructions[i], {
+			size: 60,
+			fill: 0xFFFFFF
+		});
+		instructionText.anchor.set(0.5, 0.5);
+		instructionText.x = 1024;
+		instructionText.y = 1100 + i * 80;
+		introScreen.addChild(instructionText);
+	}
+	// Start button
+	var buttonBg = LK.getAsset('barrier', {
+		anchorX: 0.5,
+		anchorY: 0.5,
+		scaleX: 1.5,
+		scaleY: 0.8,
+		tint: 0x00AA00
+	});
+	buttonBg.x = 1024;
+	buttonBg.y = 1800;
+	var buttonText = new Text2('TAP TO START', {
+		size: 80,
+		fill: 0xFFFFFF
+	});
+	buttonText.anchor.set(0.5, 0.5);
+	buttonText.x = 1024;
+	buttonText.y = 1800;
+	startButton = new Container();
+	startButton.addChild(buttonBg);
+	startButton.addChild(buttonText);
+	startButton.x = 0;
+	startButton.y = 0;
+	// Add button interaction
+	startButton.down = function (x, y, obj) {
+		startGame();
+	};
+	introScreen.addChild(startButton);
+	game.addChild(introScreen);
+}
+// Start the actual game
+function startGame() {
+	gameState = 'playing';
+	if (introScreen) {
+		introScreen.destroy();
+	}
+	// Start background music
+	LK.playMusic('bgmusic');
+}
+// Show intro screen at start
+createIntroScreen();
\ No newline at end of file