/**** 
* Plugins
****/ 
var tween = LK.import("@upit/tween.v1");
var storage = LK.import("@upit/storage.v1", {
	coins: 0,
	bestDistance: 0,
	upgrade_fuel: 0,
	upgrade_armor: 0,
	upgrade_power: 0
});

/**** 
* Classes
****/ 
// Car (player vehicle)
var Car = Container.expand(function () {
	var self = Container.call(this);
	var carSprite = self.attachAsset('car', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.width = carSprite.width;
	self.height = carSprite.height;
	self.fuel = 100;
	self.maxFuel = 100;
	self.health = 100;
	self.maxHealth = 100;
	self.speed = 1.3;
	self.alive = true;
	// For drag
	self.isDragging = false;
	// For upgrades
	self.applyUpgrades = function () {
		self.maxFuel = 100 + storage.upgrade_fuel * 30;
		self.fuel = self.maxFuel;
		self.maxHealth = 100 + storage.upgrade_armor * 40;
		self.health = self.maxHealth;
		self.speed = 16 + storage.upgrade_power * 2;
	};
	self.takeDamage = function (amount) {
		self.health -= amount;
		if (self.health < 0) self.health = 0;
		if (self.health === 0) {
			self.alive = false;
		}
	};
	self.refuel = function (amount) {
		self.fuel += amount;
		if (self.fuel > self.maxFuel) self.fuel = self.maxFuel;
	};
	self.update = function () {
		// Car movement is handled in game.update
	};
	return self;
});
// Coin
var Coin = Container.expand(function () {
	var self = Container.call(this);
	var coinSprite = self.attachAsset('coin', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.width = coinSprite.width;
	self.height = coinSprite.height;
	self.speed = 1.5;
	self.collected = false;
	self.update = function () {
		self.x -= self.speed;
	};
	return self;
});
// Zombie
var Zombie = Container.expand(function () {
	var self = Container.call(this);
	var zombieSprite = self.attachAsset('zombie', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.width = zombieSprite.width;
	self.height = zombieSprite.height;
	self.speed = 0.7 + Math.random() * 0.3;
	self.alive = true;
	self.update = function () {
		self.x -= self.speed;
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x222222
});

/**** 
* Game Code
****/ 
// Music
// Sound effects
// Road
// Health Bar FG
// Health Bar BG
// Fuel Bar FG
// Fuel Bar BG
// Coin
// Zombie
// Car (player vehicle)
// Road
var road = LK.getAsset('road', {
	anchorX: 0,
	anchorY: 0,
	x: 0,
	y: 2200
});
game.addChild(road);
// Car
var car = new Car();
car.x = 400;
car.y = 2200 + 100; // Centered on road
car.applyUpgrades();
game.addChild(car);
// Arrays for zombies and coins
var zombies = [];
var coins = [];
// Distance tracking
var distance = 0;
var runActive = true;
// GUI: Distance
var distanceTxt = new Text2('0 m', {
	size: 90,
	fill: 0xFFFFFF
});
distanceTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(distanceTxt);
// GUI: Coins
var coinsTxt = new Text2(storage.coins + '', {
	size: 90,
	fill: 0xFFD700
});
coinsTxt.anchor.set(0.5, 0);
LK.gui.topRight.addChild(coinsTxt);
// GUI: Fuel Bar
var fuelBarBG = LK.getAsset('fuelBarBG', {
	anchorX: 0,
	anchorY: 0.5,
	x: 100,
	y: 120
});
var fuelBarFG = LK.getAsset('fuelBarFG', {
	anchorX: 0,
	anchorY: 0.5,
	x: 100,
	y: 120
});
LK.gui.top.addChild(fuelBarBG);
LK.gui.top.addChild(fuelBarFG);
// GUI: Health Bar
var healthBarBG = LK.getAsset('healthBarBG', {
	anchorX: 0,
	anchorY: 0.5,
	x: 100,
	y: 200
});
var healthBarFG = LK.getAsset('healthBarFG', {
	anchorX: 0,
	anchorY: 0.5,
	x: 100,
	y: 200
});
LK.gui.top.addChild(healthBarBG);
LK.gui.top.addChild(healthBarFG);
// Dragging
var dragNode = null;
function handleMove(x, y, obj) {
	if (!runActive) return;
	if (dragNode) {
		// Clamp car to road
		var minY = road.y + car.height / 2;
		var maxY = road.y + road.height - car.height / 2;
		dragNode.y = y;
		if (dragNode.y < minY) dragNode.y = minY;
		if (dragNode.y > maxY) dragNode.y = maxY;
	}
}
game.move = handleMove;
game.down = function (x, y, obj) {
	if (!runActive) return;
	// Only allow drag if touch is on car
	if (x >= car.x - car.width / 2 && x <= car.x + car.width / 2 && y >= car.y - car.height / 2 && y <= car.y + car.height / 2) {
		dragNode = car;
		handleMove(x, y, obj);
	}
};
game.up = function (x, y, obj) {
	dragNode = null;
};
// Spawn zombies
function spawnZombie() {
	var zombie = new Zombie();
	zombie.x = 2048 + 100;
	// Random vertical position on road
	var minY = road.y + zombie.height / 2;
	var maxY = road.y + road.height - zombie.height / 2;
	zombie.y = minY + Math.random() * (maxY - minY);
	zombies.push(zombie);
	game.addChild(zombie);
}
// Spawn coins
function spawnCoin() {
	var coin = new Coin();
	coin.x = 2048 + 60;
	// Random vertical position on road
	var minY = road.y + coin.height / 2;
	var maxY = road.y + road.height - coin.height / 2;
	coin.y = minY + Math.random() * (maxY - minY);
	coins.push(coin);
	game.addChild(coin);
}
// Reset run
function startRun() {
	// Remove all zombies and coins
	for (var i = 0; i < zombies.length; ++i) zombies[i].destroy();
	for (var i = 0; i < coins.length; ++i) coins[i].destroy();
	zombies = [];
	coins = [];
	// Reset car
	car.applyUpgrades();
	car.x = 400;
	car.y = 2200 + 100;
	car.alive = true;
	// Reset distance
	distance = 0;
	runActive = true;
	// Update GUI
	distanceTxt.setText('0 m');
	coinsTxt.setText(storage.coins + '');
	// Reset bars
	updateBars();
	// Play music
	LK.playMusic('bgmusic');
}
// Update fuel and health bars
function updateBars() {
	// Fuel
	var fuelFrac = car.fuel / car.maxFuel;
	if (fuelFrac < 0) fuelFrac = 0;
	if (fuelFrac > 1) fuelFrac = 1;
	fuelBarFG.width = 400 * fuelFrac;
	// Health
	var healthFrac = car.health / car.maxHealth;
	if (healthFrac < 0) healthFrac = 0;
	if (healthFrac > 1) healthFrac = 1;
	healthBarFG.width = 400 * healthFrac;
}
// Game update
game.update = function () {
	if (!runActive) return;
	// Move car forward
	car.x += car.speed * 0.22;
	if (car.x > 800) car.x = 800; // Car stays at 800, world scrolls
	// Scroll world: move all objects left by car.speed
	for (var i = 0; i < zombies.length; ++i) zombies[i].x -= car.speed * 0.13;
	for (var i = 0; i < coins.length; ++i) coins[i].x -= car.speed * 0.13;
	// Fuel consumption
	car.fuel -= 0.022 + 0.0015 * car.speed;
	if (car.fuel < 0) car.fuel = 0;
	// Distance
	distance += car.speed * 0.13;
	distanceTxt.setText(parseInt(distance / 10) + ' m');
	// Spawn zombies
	if (LK.ticks % 45 === 0) {
		spawnZombie();
	}
	// Spawn coins
	if (LK.ticks % 90 === 0) {
		spawnCoin();
	}
	// Update zombies
	for (var i = zombies.length - 1; i >= 0; --i) {
		var z = zombies[i];
		z.update();
		// Remove if off screen
		if (z.x < -200) {
			z.destroy();
			zombies.splice(i, 1);
			continue;
		}
		// Collision with car
		if (car.alive && z.alive && car.intersects(z)) {
			z.alive = false;
			LK.getSound('zombiehit').play();
			tween(z, {
				alpha: 0
			}, {
				duration: 300,
				onFinish: function onFinish() {
					z.destroy();
				}
			});
			zombies.splice(i, 1);
			// Damage car
			car.takeDamage(20 - storage.upgrade_armor * 3);
			// Flash car
			LK.effects.flashObject(car, 0xff0000, 300);
			// Bump car back
			tween(car, {
				x: car.x - 40
			}, {
				duration: 120,
				easing: tween.easeOut
			});
			// If car dead, end run
			if (!car.alive) {
				endRun();
				return;
			}
		}
	}
	// Update coins
	for (var i = coins.length - 1; i >= 0; --i) {
		var c = coins[i];
		c.update();
		// Remove if off screen
		if (c.x < -100) {
			c.destroy();
			coins.splice(i, 1);
			continue;
		}
		// Collect coin
		if (!c.collected && car.intersects(c)) {
			c.collected = true;
			LK.getSound('coin').play();
			storage.coins += 1;
			coinsTxt.setText(storage.coins + '');
			tween(c, {
				alpha: 0,
				scaleX: 1.5,
				scaleY: 1.5
			}, {
				duration: 200,
				onFinish: function onFinish() {
					c.destroy();
				}
			});
			coins.splice(i, 1);
		}
	}
	// Update bars
	updateBars();
	// Out of fuel
	if (car.fuel <= 0) {
		car.fuel = 0;
		endRun();
		return;
	}
};
// End run
function endRun() {
	runActive = false;
	// Save best distance
	var meters = parseInt(distance / 10);
	if (meters > storage.bestDistance) storage.bestDistance = meters;
	// Show game over
	LK.effects.flashScreen(0xff0000, 800);
	LK.showGameOver();
	LK.stopMusic();
}
// On game over, reset run
LK.on('gameover', function () {
	startRun();
});
// On you win (not used, but for completeness)
LK.on('youwin', function () {
	startRun();
});
// Start first run
startRun();

===================================================================
--- original.js
+++ change.js
@@ -25,9 +25,9 @@
 	self.fuel = 100;
 	self.maxFuel = 100;
 	self.health = 100;
 	self.maxHealth = 100;
-	self.speed = 1.8;
+	self.speed = 1.3;
 	self.alive = true;
 	// For drag
 	self.isDragging = false;
 	// For upgrades
@@ -62,9 +62,9 @@
 		anchorY: 0.5
 	});
 	self.width = coinSprite.width;
 	self.height = coinSprite.height;
-	self.speed = 2.2;
+	self.speed = 1.5;
 	self.collected = false;
 	self.update = function () {
 		self.x -= self.speed;
 	};
@@ -78,9 +78,9 @@
 		anchorY: 0.5
 	});
 	self.width = zombieSprite.width;
 	self.height = zombieSprite.height;
-	self.speed = 1.0 + Math.random() * 0.5;
+	self.speed = 0.7 + Math.random() * 0.3;
 	self.alive = true;
 	self.update = function () {
 		self.x -= self.speed;
 	};
@@ -257,18 +257,18 @@
 // Game update
 game.update = function () {
 	if (!runActive) return;
 	// Move car forward
-	car.x += car.speed * 0.32;
+	car.x += car.speed * 0.22;
 	if (car.x > 800) car.x = 800; // Car stays at 800, world scrolls
 	// Scroll world: move all objects left by car.speed
-	for (var i = 0; i < zombies.length; ++i) zombies[i].x -= car.speed * 0.19;
-	for (var i = 0; i < coins.length; ++i) coins[i].x -= car.speed * 0.19;
+	for (var i = 0; i < zombies.length; ++i) zombies[i].x -= car.speed * 0.13;
+	for (var i = 0; i < coins.length; ++i) coins[i].x -= car.speed * 0.13;
 	// Fuel consumption
-	car.fuel -= 0.032 + 0.002 * car.speed;
+	car.fuel -= 0.022 + 0.0015 * car.speed;
 	if (car.fuel < 0) car.fuel = 0;
 	// Distance
-	distance += car.speed * 0.19;
+	distance += car.speed * 0.13;
 	distanceTxt.setText(parseInt(distance / 10) + ' m');
 	// Spawn zombies
 	if (LK.ticks % 45 === 0) {
 		spawnZombie();