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

/**** 
* Classes
****/ 
var Background = Container.expand(function () {
	var self = Container.call(this);
	self.backgroundLayers = [];
	self.currentTheme = 0;
	self.themes = ['background1', 'background2', 'background3'];
	self.transitionTimer = 0;
	self.transitionDuration = 1800; // 30 seconds at 60fps
	// Create initial background
	var bg1 = self.attachAsset(self.themes[self.currentTheme], {
		anchorX: 0,
		anchorY: 0
	});
	self.backgroundLayers.push(bg1);
	self.update = function () {
		self.transitionTimer++;
		if (self.transitionTimer >= self.transitionDuration) {
			self.transitionTimer = 0;
			self.currentTheme = (self.currentTheme + 1) % self.themes.length;
			// Create new background for transition
			var newBg = LK.getAsset(self.themes[self.currentTheme], {
				anchorX: 0,
				anchorY: 0,
				alpha: 0
			});
			self.addChild(newBg);
			self.backgroundLayers.push(newBg);
			// Fade in new background
			tween(newBg, {
				alpha: 1
			}, {
				duration: 2000
			});
			// Fade out old backgrounds
			for (var i = 0; i < self.backgroundLayers.length - 1; i++) {
				var oldBg = self.backgroundLayers[i];
				tween(oldBg, {
					alpha: 0
				}, {
					duration: 2000,
					onFinish: function onFinish() {
						oldBg.destroy();
					}
				});
			}
			// Keep only the new background in array
			self.backgroundLayers = [newBg];
		}
	};
	return self;
});
var Bird = Container.expand(function () {
	var self = Container.call(this);
	var birdGraphics = self.attachAsset('bird', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.velocityY = 0;
	self.gravity = 0.8;
	self.flapPower = -15;
	self.maxFallSpeed = 15;
	self.isDead = false;
	self.flap = function () {
		if (!self.isDead) {
			self.velocityY = self.flapPower;
			LK.getSound('flap').play();
			// Wing flap animation
			tween(birdGraphics, {
				scaleY: 1.2
			}, {
				duration: 100,
				onFinish: function onFinish() {
					tween(birdGraphics, {
						scaleY: 1.0
					}, {
						duration: 100
					});
				}
			});
		}
	};
	self.update = function () {
		if (!self.isDead) {
			// Apply gravity
			self.velocityY += self.gravity;
			// Limit fall speed
			if (self.velocityY > self.maxFallSpeed) {
				self.velocityY = self.maxFallSpeed;
			}
			// Update position
			self.y += self.velocityY;
			// Rotate bird based on velocity
			var targetRotation = Math.min(Math.max(self.velocityY * 0.1, -0.5), 1.5);
			birdGraphics.rotation = targetRotation;
			// Allow bird to pass through top of screen
			if (self.y < -30) {
				self.y = 2732 + 30; // Wrap to bottom of screen
			}
			// Check collision with ground
			if (self.y > 2732 - 150 - 30) {
				self.y = 2732 - 150 - 30;
				self.die();
			}
		}
	};
	self.die = function () {
		if (!self.isDead) {
			self.isDead = true;
			LK.getSound('hit').play();
			// Death animation
			tween(birdGraphics, {
				rotation: Math.PI,
				alpha: 0.7
			}, {
				duration: 1000
			});
			tween(self, {
				y: 2732 - 150 - 30
			}, {
				duration: 1000,
				easing: tween.bounceOut
			});
		}
	};
	return self;
});
var Cloud = Container.expand(function () {
	var self = Container.call(this);
	var cloudGraphics = self.attachAsset('cloud', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = -1;
	self.update = function () {
		self.x += self.speed;
	};
	return self;
});
var Pipe = Container.expand(function () {
	var self = Container.call(this);
	self.gapSize = 480;
	self.speed = -4;
	self.scored = false;
	// Top pipe - extends from top of screen to gap
	var topPipe = self.attachAsset('pipe', {
		anchorX: 0.5,
		anchorY: 0
	});
	// Bottom pipe - extends from gap to bottom of screen  
	var bottomPipe = self.attachAsset('pipe', {
		anchorX: 0.5,
		anchorY: 0
	});
	self.setGapPosition = function (gapY) {
		// Position and scale top pipe to fill from top to gap start
		topPipe.y = 0;
		topPipe.scaleY = (gapY - self.gapSize / 2) / 2732;
		// Position and scale bottom pipe to fill from gap end to ground
		bottomPipe.y = gapY + self.gapSize / 2;
		bottomPipe.scaleY = (2732 - 150 - (gapY + self.gapSize / 2)) / 2732;
	};
	self.update = function () {
		self.x += self.speed;
	};
	return self;
});

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

/**** 
* Game Code
****/ 
// Game variables
var bird;
var pipes = [];
var clouds = [];
var ground;
var backgroundSystem;
var gameStarted = false;
var pipeSpawnTimer = 0;
var cloudSpawnTimer = 0;
var difficultyTimer = 0;
// UI
var scoreTxt = new Text2('0', {
	size: 120,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
scoreTxt.y = 100;
var instructionTxt = new Text2('TAP TO FLAP', {
	size: 80,
	fill: 0xFFFFFF
});
instructionTxt.anchor.set(0.5, 0.5);
LK.gui.center.addChild(instructionTxt);
// Initialize background system
backgroundSystem = game.addChild(new Background());
// Create ground
ground = game.addChild(LK.getAsset('ground', {
	anchorX: 0,
	anchorY: 0,
	x: 0,
	y: 2732 - 150
}));
// Create bird
bird = game.addChild(new Bird());
bird.x = 300;
bird.y = 1366;
// Initial clouds
for (var i = 0; i < 3; i++) {
	var cloud = game.addChild(new Cloud());
	cloud.x = Math.random() * 2048;
	cloud.y = Math.random() * 800 + 200;
	cloud.alpha = 0.7;
	clouds.push(cloud);
}
function startGame() {
	if (!gameStarted) {
		gameStarted = true;
		instructionTxt.visible = false;
	}
}
function spawnPipe() {
	var pipe = game.addChild(new Pipe());
	pipe.x = 2048 + 60;
	// Dynamic difficulty - reduce gap size over time
	var difficultyFactor = Math.min(LK.getScore() * 0.02, 0.3);
	pipe.gapSize = Math.max(430 - difficultyFactor * 100, 360);
	var gapY = Math.random() * (1800 - 600) + 600;
	pipe.setGapPosition(gapY);
	pipes.push(pipe);
}
function spawnCloud() {
	var cloud = game.addChild(new Cloud());
	cloud.x = 2048 + 100;
	cloud.y = Math.random() * 1000 + 200;
	cloud.alpha = 0.6;
	cloud.scaleX = Math.random() * 0.5 + 0.5;
	cloud.scaleY = Math.random() * 0.5 + 0.5;
	clouds.push(cloud);
}
// Game input
game.down = function (x, y, obj) {
	if (!gameStarted) {
		startGame();
	}
	bird.flap();
};
// Game update loop
game.update = function () {
	// Update background system
	backgroundSystem.update();
	if (gameStarted && !bird.isDead) {
		// Spawn pipes
		pipeSpawnTimer++;
		if (pipeSpawnTimer >= 150) {
			// Every 2.5 seconds
			pipeSpawnTimer = 0;
			spawnPipe();
		}
		// Spawn clouds
		cloudSpawnTimer++;
		if (cloudSpawnTimer >= 240) {
			// Every 4 seconds
			cloudSpawnTimer = 0;
			spawnCloud();
		}
		// Update and check pipes
		for (var i = pipes.length - 1; i >= 0; i--) {
			var pipe = pipes[i];
			// Check for scoring
			if (!pipe.scored && pipe.x + 60 < bird.x) {
				pipe.scored = true;
				LK.setScore(LK.getScore() + 1);
				scoreTxt.setText(LK.getScore());
				LK.getSound('score').play();
			}
			// Check collision with bird
			if (pipe.intersects(bird)) {
				bird.die();
				LK.effects.flashScreen(0xff0000, 500);
				LK.showGameOver(); // Immediate game over when touching pipe
			}
			// Remove off-screen pipes
			if (pipe.x < -150) {
				pipe.destroy();
				pipes.splice(i, 1);
			}
		}
		// Update and manage clouds
		for (var j = clouds.length - 1; j >= 0; j--) {
			var cloud = clouds[j];
			if (cloud.x < -250) {
				cloud.destroy();
				clouds.splice(j, 1);
			}
		}
	}
	// Show game over immediately when bird dies from hitting ground
	if (bird.isDead && bird.y >= 2732 - 150 - 30) {
		LK.effects.flashScreen(0xff0000, 500);
		LK.showGameOver();
	}
};

===================================================================
--- original.js
+++ change.js
@@ -265,10 +265,10 @@
 	backgroundSystem.update();
 	if (gameStarted && !bird.isDead) {
 		// Spawn pipes
 		pipeSpawnTimer++;
-		if (pipeSpawnTimer >= 120) {
-			// Every 2 seconds
+		if (pipeSpawnTimer >= 150) {
+			// Every 2.5 seconds
 			pipeSpawnTimer = 0;
 			spawnPipe();
 		}
 		// Spawn clouds