/**** 
* Plugins
****/ 
var tween = LK.import("@upit/tween.v1");
var storage = LK.import("@upit/storage.v1", {
	bestScore: 0
});

/**** 
* Classes
****/ 
// Player Car
var Car = Container.expand(function () {
	var self = Container.call(this);
	var carAsset = self.attachAsset('car', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// For collision box, use the car asset's size
	self.width = carAsset.width;
	self.height = carAsset.height;
	return self;
});
// Obstacle
var Obstacle = Container.expand(function () {
	var self = Container.call(this);
	var obsAsset = self.attachAsset('obstacle', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.width = obsAsset.width;
	self.height = obsAsset.height;
	// For collision
	return self;
});
// Road Stripe
var Stripe = Container.expand(function () {
	var self = Container.call(this);
	var stripeAsset = self.attachAsset('stripe', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.width = stripeAsset.width;
	self.height = stripeAsset.height;
	return self;
});

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

/**** 
* Game Code
****/ 
// Road stripes
// Coin
// Obstacle
// Car (player)
// Game area
var GAME_WIDTH = 2048;
var GAME_HEIGHT = 2732;
var ROAD_WIDTH = 1200;
var ROAD_X = (GAME_WIDTH - ROAD_WIDTH) / 2;
var ROAD_Y = 0;
var ROAD_HEIGHT = GAME_HEIGHT;
// Player car
var car = new Car();
car.x = GAME_WIDTH / 2;
car.y = GAME_HEIGHT - 500;
game.addChild(car);
// Road stripes
var stripes = [];
var stripeSpacing = 400;
for (var i = 0; i < 8; i++) {
	var stripe = new Stripe();
	stripe.x = GAME_WIDTH / 2;
	stripe.y = i * stripeSpacing + 200;
	stripes.push(stripe);
	game.addChild(stripe);
}
// Obstacles
var obstacles = [];
// Score
var score = 0;
var scoreTxt = new Text2('0', {
	size: 120,
	fill: "#fff"
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Best score
var bestScore = storage.bestScore || 0;
var bestScoreTxt = new Text2('Best: ' + bestScore, {
	size: 60,
	fill: "#fff"
});
bestScoreTxt.anchor.set(0.5, 0);
bestScoreTxt.y = 120;
LK.gui.top.addChild(bestScoreTxt);
// Game speed
var baseSpeed = 18;
var speed = baseSpeed;
var speedIncreaseEvery = 600; // ticks
var maxSpeed = 48;
// Dragging
var dragCar = false;
var dragOffsetX = 0;
// Touch controls
function clamp(val, min, max) {
	return val < min ? min : val > max ? max : val;
}
function handleMove(x, y, obj) {
	if (dragCar) {
		// Clamp car within road
		var minX = ROAD_X + car.width / 2 + 20;
		var maxX = ROAD_X + ROAD_WIDTH - car.width / 2 - 20;
		car.x = clamp(x - dragOffsetX, minX, maxX);
	}
}
game.move = handleMove;
game.down = function (x, y, obj) {
	// Only start drag if touch is on car
	var local = car.toLocal(game.toGlobal({
		x: x,
		y: y
	}));
	if (local.x >= -car.width / 2 && local.x <= car.width / 2 && local.y >= -car.height / 2 && local.y <= car.height / 2) {
		dragCar = true;
		dragOffsetX = x - car.x;
	}
};
game.up = function (x, y, obj) {
	dragCar = false;
};
// Spawning
var obstacleTimer = 0;
var coinTimer = 0;
function spawnObstacle() {
	var obs = new Obstacle();
	// Random lane
	var lanes = 4;
	var laneWidth = ROAD_WIDTH / lanes;
	var lane = Math.floor(Math.random() * lanes);
	obs.x = ROAD_X + laneWidth * (lane + 0.5);
	obs.y = -obs.height;
	obstacles.push(obs);
	game.addChild(obs);
}
// Main update loop
game.update = function () {
	// Speed up over time
	if (LK.ticks % speedIncreaseEvery === 0 && speed < maxSpeed) {
		speed += 2;
	}
	// Move stripes
	for (var i = 0; i < stripes.length; i++) {
		stripes[i].y += speed;
		if (stripes[i].y > GAME_HEIGHT + stripes[i].height / 2) {
			stripes[i].y -= stripeSpacing * stripes.length;
		}
	}
	// Spawn obstacles
	obstacleTimer += 1;
	if (obstacleTimer > 40 + Math.floor(60 * baseSpeed / speed)) {
		spawnObstacle();
		obstacleTimer = 0;
	}
	// Distance-based scoring
	score += Math.floor(speed / 6);
	scoreTxt.setText(score);
	// Move obstacles
	for (var i = obstacles.length - 1; i >= 0; i--) {
		var obs = obstacles[i];
		obs.y += speed;
		// Remove if off screen
		if (obs.y - obs.height / 2 > GAME_HEIGHT + 100) {
			obs.destroy();
			obstacles.splice(i, 1);
			continue;
		}
		// Collision with car
		if (car.intersects(obs)) {
			// Flash and game over
			LK.effects.flashScreen(0xff0000, 800);
			if (score > bestScore) {
				storage.bestScore = score;
			}
			LK.showGameOver();
			return;
		}
	}
};
// Reset score on new game
score = 0;
scoreTxt.setText(score);
bestScore = storage.bestScore || 0;
bestScoreTxt.setText('Best: ' + bestScore);

===================================================================
--- original.js
+++ change.js
@@ -20,19 +20,8 @@
 	self.width = carAsset.width;
 	self.height = carAsset.height;
 	return self;
 });
-// Coin
-var Coin = Container.expand(function () {
-	var self = Container.call(this);
-	var coinAsset = self.attachAsset('coin', {
-		anchorX: 0.5,
-		anchorY: 0.5
-	});
-	self.width = coinAsset.width;
-	self.height = coinAsset.height;
-	return self;
-});
 // Obstacle
 var Obstacle = Container.expand(function () {
 	var self = Container.call(this);
 	var obsAsset = self.attachAsset('obstacle', {
@@ -91,11 +80,10 @@
 	stripe.y = i * stripeSpacing + 200;
 	stripes.push(stripe);
 	game.addChild(stripe);
 }
-// Obstacles and coins
+// Obstacles
 var obstacles = [];
-var coins = [];
 // Score
 var score = 0;
 var scoreTxt = new Text2('0', {
 	size: 120,
@@ -160,18 +148,8 @@
 	obs.y = -obs.height;
 	obstacles.push(obs);
 	game.addChild(obs);
 }
-function spawnCoin() {
-	var coin = new Coin();
-	var lanes = 4;
-	var laneWidth = ROAD_WIDTH / lanes;
-	var lane = Math.floor(Math.random() * lanes);
-	coin.x = ROAD_X + laneWidth * (lane + 0.5);
-	coin.y = -coin.height;
-	coins.push(coin);
-	game.addChild(coin);
-}
 // Main update loop
 game.update = function () {
 	// Speed up over time
 	if (LK.ticks % speedIncreaseEvery === 0 && speed < maxSpeed) {
@@ -189,14 +167,11 @@
 	if (obstacleTimer > 40 + Math.floor(60 * baseSpeed / speed)) {
 		spawnObstacle();
 		obstacleTimer = 0;
 	}
-	// Spawn coins
-	coinTimer += 1;
-	if (coinTimer > 90 + Math.floor(120 * baseSpeed / speed)) {
-		spawnCoin();
-		coinTimer = 0;
-	}
+	// Distance-based scoring
+	score += Math.floor(speed / 6);
+	scoreTxt.setText(score);
 	// Move obstacles
 	for (var i = obstacles.length - 1; i >= 0; i--) {
 		var obs = obstacles[i];
 		obs.y += speed;
@@ -216,43 +191,8 @@
 			LK.showGameOver();
 			return;
 		}
 	}
-	// Move coins
-	for (var i = coins.length - 1; i >= 0; i--) {
-		var coin = coins[i];
-		coin.y += speed;
-		// Remove if off screen
-		if (coin.y - coin.height / 2 > GAME_HEIGHT + 100) {
-			coin.destroy();
-			coins.splice(i, 1);
-			continue;
-		}
-		// Collect coin
-		if (car.intersects(coin)) {
-			score += 1;
-			scoreTxt.setText(score);
-			if (score > bestScore) {
-				bestScore = score;
-				bestScoreTxt.setText('Best: ' + bestScore);
-				storage.bestScore = bestScore;
-			}
-			// Animate coin
-			tween(coin, {
-				scaleX: 1.5,
-				scaleY: 1.5,
-				alpha: 0
-			}, {
-				duration: 200,
-				easing: tween.easeOut,
-				onFinish: function onFinish() {
-					coin.destroy();
-				}
-			});
-			coins.splice(i, 1);
-			continue;
-		}
-	}
 };
 // Reset score on new game
 score = 0;
 scoreTxt.setText(score);