/**** 
* Classes
****/ 
// Coin class
var Coin = Container.expand(function () {
	var self = Container.call(this);
	var coinGraphics = self.attachAsset('coin', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speedX = -5;
	self.update = function () {
		self.x += self.speedX;
		if (self.x < -coinGraphics.width / 2) {
			self.destroy();
		}
	};
});
//<Assets used in the game will automatically appear here>
//<Write imports for supported plugins here>
// Jetpack character class
var JetpackCharacter = Container.expand(function () {
	var self = Container.call(this);
	var characterGraphics = self.attachAsset('jetpackCharacter', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speedY = 0;
	self.gravity = 0.5;
	self.flapStrength = -10;
	self.update = function () {
		self.speedY += self.gravity;
		self.y += self.speedY;
		if (self.y > 2732 - characterGraphics.height / 2) {
			self.y = 2732 - characterGraphics.height / 2;
			self.speedY = 0;
		}
		if (self.y < characterGraphics.height / 2) {
			self.y = characterGraphics.height / 2;
			self.speedY = 0;
		}
	};
	self.flap = function () {
		self.speedY = self.flapStrength;
	};
});
// Obstacle class
var Obstacle = Container.expand(function () {
	var self = Container.call(this);
	var obstacleGraphics = self.attachAsset('obstacle', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speedX = -5;
	self.update = function () {
		self.x += self.speedX;
		self.y += Math.sin(self.x / 100) * 5; // Add vertical oscillation based on the x position
		if (self.x < -obstacleGraphics.width / 2) {
			self.destroy();
		}
	};
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x87CEEB // Sky blue background
});

/**** 
* Game Code
****/ 
var background = game.addChild(LK.getAsset('background', {
	anchorX: 0,
	anchorY: 0
}));
var jetpackCharacter = game.addChild(new JetpackCharacter());
jetpackCharacter.x = 200;
jetpackCharacter.y = 1366;
var obstacles = [];
var coins = [];
var score = 0;
var scoreTxt = new Text2('Score: 0', {
	size: 100,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
game.down = function (x, y, obj) {
	jetpackCharacter.flap();
	LK.getSound('JetpackFly').play();
};
game.update = function () {
	jetpackCharacter.update();
	if (LK.ticks % 100 == 0) {
		var newObstacle = new Obstacle();
		newObstacle.x = 2048 + newObstacle.width / 2;
		newObstacle.y = Math.random() * (2732 - 400) + 200;
		obstacles.push(newObstacle);
		game.addChild(newObstacle);
	}
	if (LK.ticks % 150 == 0) {
		var newCoin = new Coin();
		newCoin.x = 2048 + newCoin.width / 2;
		newCoin.y = Math.random() * (2732 - 400) + 200;
		coins.push(newCoin);
		game.addChild(newCoin);
	}
	for (var i = obstacles.length - 1; i >= 0; i--) {
		obstacles[i].update();
		if (jetpackCharacter.intersects(obstacles[i])) {
			LK.effects.flashScreen(0xff0000, 1000);
			LK.showGameOver();
		}
	}
	for (var j = coins.length - 1; j >= 0; j--) {
		coins[j].update();
		if (jetpackCharacter.intersects(coins[j])) {
			score += 10;
			scoreTxt.setText('Score: ' + score);
			LK.getSound('CollectCoin').play();
			coins[j].destroy();
			coins.splice(j, 1);
		}
	}
};

===================================================================
--- original.js
+++ change.js
@@ -51,21 +51,14 @@
 		anchorX: 0.5,
 		anchorY: 0.5
 	});
 	self.speedX = -5;
-	self.speedY = 0;
 	self.update = function () {
 		self.x += self.speedX;
-		self.y += self.speedY;
+		self.y += Math.sin(self.x / 100) * 5; // Add vertical oscillation based on the x position
 		if (self.x < -obstacleGraphics.width / 2) {
 			self.destroy();
 		}
-		if (self.y > 2732 - obstacleGraphics.height / 2) {
-			self.speedY = -self.speedY;
-		}
-		if (self.y < obstacleGraphics.height / 2) {
-			self.speedY = -self.speedY;
-		}
 	};
 });
 
 /****