/**** 
* Classes
****/
// Hero class
var Hero = Container.expand(function () {
	var self = Container.call(this);
	var heroGraphics = self.createAsset('hero', 'Hero character', 0.5, 0.5);
	self.speed = 9;
	self.jumpPower = -18;
	self.gravity = 0.5;
	self.isJumping = false;
	self.velocityY = 0;
	self.update = function () {
		// Apply gravity
		if (self.isJumping || self.isFalling) {
			self.velocityY += self.gravity;
			self.y += self.velocityY;
			if (self.y > game.height - heroGraphics.height / 2) {
				self.isJumping = false;
				self.isFalling = false;

				// Create a trail particle every few ticks
				if (LK.ticks % 5 == 0) {
					self.createTrail();
				}
				self.jumpCount = 0;
				self.y = game.height - heroGraphics.height / 2;
			}
		}
		self.isFalling = false;
	};
	self.jumpCount = 0;
	self.maxJumps = 2;
	self.isFalling = false;
	self.jump = function () {
		if (self.jumpCount < self.maxJumps) {
			self.jumpCount++;
			self.isJumping = true;
			self.velocityY = self.jumpPower;
		}
	};
	self.fallQuickly = function () {
		self.isFalling = true;
		self.velocityY = self.gravity * 50;
	};
	self.createTrail = function () {
		var particle = new Particle();
		particle.x = self.x;
		particle.y = self.y + self.height / 4;
		game.addChild(particle);
	};
});
// Obstacle class
var Obstacle = Container.expand(function () {
	var self = Container.call(this);
	var obstacleGraphics = self.createAsset('obstacle', 'Obstacle', 0.5, 1);
	self.speed = -10;
	self.move = function () {
		self.x += self.speed;
	};
});
var Particle = Container.expand(function () {
	var self = Container.call(this);
	var particleGraphics = self.createAsset('particle', 'Particle', 0.5, 0.5);
	self.lifetime = 60; // Lifetime of the particle in ticks
	self.fadeOut = function () {
		if (self.lifetime > 0) {
			self.lifetime--;
			particleGraphics.alpha = self.lifetime / 60;
		} else {
			self.destroy();
		}
	};
});

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

/**** 
* Game Code
****/
// Initialize hero
var hero = game.addChild(new Hero());
hero.x = game.width / 4;
hero.y = game.height - hero.height / 2;

// Initialize obstacles array
var obstacles = [];

// Initialize score
var score = 0;
var scoreTxt = new Text2(score.toString(), {
	size: 150,
	fill: "#ffffff"
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);

// Game tick event
LK.on('tick', function () {
	// Update hero
	hero.update();

	// Move and check obstacles
	for (var i = obstacles.length - 1; i >= 0; i--) {
		obstacles[i].move();
		// Check for collision with hero
		if (hero.intersects(obstacles[i])) {
			// Check if hero jumps on top of the obstacle
			if (hero.y + hero.height / 2 <= obstacles[i].y - obstacles[i].height / 2 && hero.velocityY > 0) {
				// Remove the obstacle if jumped on top
				obstacles[i].destroy();
				obstacles.splice(i, 1);
			} else {
				// Game over if collided from the side
				LK.effects.flashScreen(0xff0000, 1000);
				LK.showGameOver();
				return;
			}
		}
		// Remove off-screen obstacles
		if (obstacles[i].x < -obstacles[i].width) {
			obstacles[i].destroy();
			obstacles.splice(i, 1);
		}
	}

	// Increment score
	score++;
	scoreTxt.setText(score.toString());

	// Add new obstacles
	if (LK.ticks % 100 == 0) {
		var obstacle = new Obstacle();
		obstacle.x = game.width;
		obstacle.y = game.height;
		obstacles.push(obstacle);
		game.addChild(obstacle);
	}
});

// Prepare for swipe detection
var swipeStart = null;
var swipeThreshold = 50; // Minimum distance for a swipe to count

// Touch start event to record the start position of a swipe
game.on('down', function (obj) {
	var event = obj.event;
	swipeStart = event.getLocalPosition(game);
});

// Touch end event to detect a swipe
game.on('up', function (obj) {
	var event = obj.event;
	var swipeEnd = event.getLocalPosition(game);
	if (swipeStart) {
		if (Math.abs(swipeEnd.y - swipeStart.y) > swipeThreshold) {
			if (swipeStart.y > swipeEnd.y) {
				hero.jump();
			} else if (swipeStart.y < swipeEnd.y) {
				hero.fallQuickly();
			}
		}
	}
	swipeStart = null; // Reset swipe start position
});

===================================================================
--- original.js
+++ change.js
@@ -17,8 +17,13 @@
 			self.y += self.velocityY;
 			if (self.y > game.height - heroGraphics.height / 2) {
 				self.isJumping = false;
 				self.isFalling = false;
+
+				// Create a trail particle every few ticks
+				if (LK.ticks % 5 == 0) {
+					self.createTrail();
+				}
 				self.jumpCount = 0;
 				self.y = game.height - heroGraphics.height / 2;
 			}
 		}
@@ -37,8 +42,14 @@
 	self.fallQuickly = function () {
 		self.isFalling = true;
 		self.velocityY = self.gravity * 50;
 	};
+	self.createTrail = function () {
+		var particle = new Particle();
+		particle.x = self.x;
+		particle.y = self.y + self.height / 4;
+		game.addChild(particle);
+	};
 });
 // Obstacle class
 var Obstacle = Container.expand(function () {
 	var self = Container.call(this);
@@ -47,8 +58,21 @@
 	self.move = function () {
 		self.x += self.speed;
 	};
 });
+var Particle = Container.expand(function () {
+	var self = Container.call(this);
+	var particleGraphics = self.createAsset('particle', 'Particle', 0.5, 0.5);
+	self.lifetime = 60; // Lifetime of the particle in ticks
+	self.fadeOut = function () {
+		if (self.lifetime > 0) {
+			self.lifetime--;
+			particleGraphics.alpha = self.lifetime / 60;
+		} else {
+			self.destroy();
+		}
+	};
+});
 
 /**** 
 * Initialize Game
 ****/