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

/**** 
* Classes
****/ 
var Bird = Container.expand(function () {
	var self = Container.call(this);
	var birdGraphics = self.attachAsset('bird', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = Math.random() * 2 + 1;
	self.direction = Math.random() > 0.5 ? 1 : -1;
	self.flapTimer = 0;
	self.update = function () {
		self.x += self.speed * self.direction;
		// Flap animation
		self.flapTimer++;
		if (self.flapTimer < 15) {
			birdGraphics.scaleY = 0.8;
		} else if (self.flapTimer < 30) {
			birdGraphics.scaleY = 1.2;
		} else {
			self.flapTimer = 0;
		}
		// Remove if off screen
		if (self.x < -50 || self.x > 2098) {
			self.destroy();
			birds.splice(birds.indexOf(self), 1);
		}
	};
	return self;
});
var Boss = Container.expand(function () {
	var self = Container.call(this);
	var bossGraphics = self.attachAsset('boss', {
		anchorX: 0.5,
		anchorY: 1.0
	});
	self.health = 300;
	self.maxHealth = 300;
	self.speed = 1.5;
	self.attackDamage = 20;
	self.attackCooldown = 0;
	self.maxAttackCooldown = 120;
	self.direction = 1;
	self.lastIntersecting = false;
	self.update = function () {
		// Move back and forth
		self.x += self.speed * self.direction;
		if (self.x <= 200 || self.x >= 1848) {
			self.direction *= -1;
		}
		// Attack monster
		if (self.attackCooldown > 0) {
			self.attackCooldown--;
		}
		var currentIntersecting = self.intersects(monster);
		if (currentIntersecting && self.attackCooldown <= 0) {
			monster.takeDamage(self.attackDamage);
			LK.getSound('attack').play();
			self.attackCooldown = self.maxAttackCooldown;
		}
		// Check if monster jumps on boss - monster takes no damage when landing on boss
		if (!self.lastIntersecting && currentIntersecting && monster.velocityY > 0) {
			self.takeDamage(50);
			// Monster doesn't take damage when landing on boss
		}
		self.lastIntersecting = currentIntersecting;
	};
	self.takeDamage = function (damage) {
		self.health -= damage;
		LK.getSound('boss_hit').play();
		LK.effects.flashObject(self, 0xff0000, 300);
		if (self.health <= 0) {
			LK.setScore(LK.getScore() + 1000);
			self.destroy();
			boss = null;
			level++;
			startLevel();
		}
	};
	return self;
});
var Building = Container.expand(function () {
	var self = Container.call(this);
	self.heightLevel = Math.floor(Math.random() * 3) + 1; // 1, 2, or 3
	self.assetNames = ['building_small', 'building_medium', 'building_large'];
	self.buildingHeights = [80, 160, 240];
	self.buildingType = Math.floor(Math.random() * 3); // 0=tech, 1=ottoman, 2=cave
	self.buildingTypes = ['tech', 'ottoman', 'cave'];
	self.projectileTypes = ['rocket', 'cannonball', 'arrow'];
	self.attackCooldown = 0;
	self.maxAttackCooldown = 450; // 7.5 seconds at 60fps
	var buildingGraphics = self.attachAsset(self.assetNames[self.heightLevel - 1], {
		anchorX: 0.5,
		anchorY: 1.0
	});
	self.lastIntersecting = false;
	self.update = function () {
		// Check collision with monster
		var currentIntersecting = self.intersects(monster);
		if (!self.lastIntersecting && currentIntersecting && monster.velocityY > 0) {
			self.stomp();
		}
		self.lastIntersecting = currentIntersecting;
		// Attack monster with projectiles
		if (self.attackCooldown > 0) {
			self.attackCooldown--;
		}
		if (self.attackCooldown <= 0) {
			self.fireProjectile();
			self.attackCooldown = self.maxAttackCooldown;
		}
	};
	self.stomp = function () {
		LK.getSound('stomp').play();
		LK.setScore(LK.getScore() + 10);
		// Monster doesn't take damage when stomping on buildings
		// Shrink building by one level
		self.heightLevel--;
		if (self.heightLevel <= 0) {
			// Building destroyed
			self.destroy();
			buildings.splice(buildings.indexOf(self), 1);
			buildingsDestroyed++;
		} else {
			// Replace with smaller building
			self.removeChild(buildingGraphics);
			buildingGraphics = self.attachAsset(self.assetNames[self.heightLevel - 1], {
				anchorX: 0.5,
				anchorY: 1.0
			});
		}
	};
	self.fireProjectile = function () {
		var projectile = new Projectile();
		// Fire projectile based on building height level: 3=rocket, 2=cannonball, 1=arrow
		if (self.heightLevel === 3) {
			projectile.type = 'rocket';
		} else if (self.heightLevel === 2) {
			projectile.type = 'cannonball';
		} else {
			projectile.type = 'arrow';
		}
		var projectileGraphics = projectile.attachAsset(projectile.type, {
			anchorX: 0.5,
			anchorY: 0.5
		});
		projectile.x = self.x;
		projectile.y = self.y - self.buildingHeights[self.heightLevel - 1] / 2;
		// Calculate direction to monster
		var dx = monster.x - projectile.x;
		var dy = monster.y - projectile.y;
		var distance = Math.sqrt(dx * dx + dy * dy);
		projectile.velocityX = dx / distance * projectile.speed;
		projectile.velocityY = dy / distance * projectile.speed;
		// Rotate projectile to face monster
		projectileGraphics.rotation = Math.atan2(dy, dx);
		projectiles.push(projectile);
		game.addChild(projectile);
	};
	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 = Math.random() * 0.5 + 0.2;
	self.alpha = Math.random() * 0.4 + 0.6;
	cloudGraphics.alpha = self.alpha;
	self.update = function () {
		self.x += self.speed;
		// Remove if off screen
		if (self.x > 2098 + 150) {
			self.destroy();
			clouds.splice(clouds.indexOf(self), 1);
		}
	};
	return self;
});
var Monster = Container.expand(function () {
	var self = Container.call(this);
	var monsterGraphics = self.attachAsset('monster', {
		anchorX: 0.5,
		anchorY: 1.0
	});
	self.velocityY = 0;
	self.isJumping = false;
	self.minJumpPower = -15;
	self.maxJumpPower = -35; // Higher than tallest building (240px)
	self.gravity = 1.2;
	self.groundY = 2500;
	self.speed = 8;
	self.health = 300;
	self.maxHealth = 300;
	self.isCharging = false;
	self.chargeStartTime = 0;
	self.maxChargeTime = 60; // 1 second at 60fps
	self.update = function () {
		// Apply gravity
		self.velocityY += self.gravity;
		self.y += self.velocityY;
		// Ground collision
		if (self.y >= self.groundY) {
			self.y = self.groundY;
			self.velocityY = 0;
			self.isJumping = false;
		}
		// Keep monster on screen
		if (self.x < 90) self.x = 90;
		if (self.x > 1958) self.x = 1958;
	};
	self.startCharging = function () {
		if (!self.isJumping && !self.isCharging) {
			self.isCharging = true;
			self.chargeStartTime = LK.ticks;
		}
	};
	self.jump = function () {
		if (self.isCharging) {
			var chargeTime = Math.min(LK.ticks - self.chargeStartTime, self.maxChargeTime);
			var chargeRatio = chargeTime / self.maxChargeTime;
			var jumpPower = self.minJumpPower + (self.maxJumpPower - self.minJumpPower) * chargeRatio;
			self.velocityY = jumpPower;
			self.isJumping = true;
			self.isCharging = false;
		}
	};
	self.takeDamage = function (damage, projectileType) {
		self.health -= damage;
		if (self.health <= 0) {
			self.health = 0;
			LK.showGameOver();
		}
		// Flash red when taking damage
		LK.effects.flashObject(self, 0xff0000, 500);
		// Different effects based on projectile type
		if (projectileType === 'arrow') {
			// Light scream for arrow
			LK.getSound('attack').play();
		} else if (projectileType === 'cannonball') {
			// Explosion effect and stronger roar for cannonball
			LK.effects.flashScreen(0xff4400, 300);
			tween(self, {
				scaleX: 1.2,
				scaleY: 1.2
			}, {
				duration: 200,
				onFinish: function onFinish() {
					tween(self, {
						scaleX: 1,
						scaleY: 1
					}, {
						duration: 200
					});
				}
			});
			LK.getSound('boss_hit').play();
		} else if (projectileType === 'rocket') {
			// Dinosaur roars loudly and big explosion for rocket
			LK.effects.flashScreen(0xff0000, 500);
			tween(self, {
				scaleX: 1.5,
				scaleY: 1.5
			}, {
				duration: 300,
				onFinish: function onFinish() {
					tween(self, {
						scaleX: 1,
						scaleY: 1
					}, {
						duration: 300
					});
				}
			});
			LK.getSound('stomp').play();
		}
	};
	return self;
});
var Projectile = Container.expand(function () {
	var self = Container.call(this);
	self.type = 'rocket'; // 'rocket', 'cannonball', 'arrow'
	self.speed = 5;
	self.damage = 10;
	self.lastIntersecting = false;
	self.velocityX = 0;
	self.velocityY = 0;
	self.update = function () {
		// Move projectile
		self.x += self.velocityX;
		self.y += self.velocityY;
		// Check collision with monster
		var currentIntersecting = self.intersects(monster);
		if (!self.lastIntersecting && currentIntersecting) {
			monster.takeDamage(self.damage, self.type);
			self.destroy();
			projectiles.splice(projectiles.indexOf(self), 1);
		}
		self.lastIntersecting = currentIntersecting;
		// Remove if off screen
		if (self.x < -50 || self.x > 2098 || self.y < -50 || self.y > 2782) {
			self.destroy();
			projectiles.splice(projectiles.indexOf(self), 1);
		}
	};
	return self;
});
var WeatherParticle = Container.expand(function () {
	var self = Container.call(this);
	self.type = 'rain'; // 'rain' or 'snow'
	self.speed = 0;
	self.particleGraphics = null;
	self.init = function (type) {
		self.type = type;
		if (type === 'rain') {
			self.particleGraphics = self.attachAsset('rainDrop', {
				anchorX: 0.5,
				anchorY: 0.5
			});
			self.speed = Math.random() * 8 + 12;
		} else {
			self.particleGraphics = self.attachAsset('snowFlake', {
				anchorX: 0.5,
				anchorY: 0.5
			});
			self.speed = Math.random() * 3 + 2;
		}
	};
	self.update = function () {
		self.y += self.speed;
		if (self.type === 'snow') {
			self.x += Math.sin(self.y * 0.01) * 0.5;
		}
		// Remove if off screen
		if (self.y > 2782) {
			self.destroy();
			weatherParticles.splice(weatherParticles.indexOf(self), 1);
		}
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x87ceeb
});

/**** 
* Game Code
****/ 
var monster;
var buildings = [];
var projectiles = [];
var boss = null;
var buildingsDestroyed = 0;
var level = 1;
var spawnTimer = 0;
var maxSpawnTimer = 180;
var birds = [];
var clouds = [];
var weatherParticles = [];
var skyBrightness = 1.0;
var skyDirection = -1;
var weatherType = 'none'; // 'none', 'rain', 'snow'
var weatherTimer = 0;
var weatherDuration = 0;
var birdSpawnTimer = 0;
var cloudSpawnTimer = 0;
// Create ground
var ground = game.addChild(LK.getAsset('ground', {
	anchorX: 0.5,
	anchorY: 1.0,
	x: 1024,
	y: 2600
}));
// Create monster
monster = game.addChild(new Monster());
monster.x = 1024;
monster.y = 2500;
// Create score display
var scoreTxt = new Text2('Score: 0', {
	size: 80,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Create health display
var healthTxt = new Text2('Health: 300', {
	size: 60,
	fill: 0xFF0000
});
healthTxt.anchor.set(0, 0);
healthTxt.x = 120;
healthTxt.y = 120;
LK.gui.topLeft.addChild(healthTxt);
// Create level display
var levelTxt = new Text2('Level: 1', {
	size: 60,
	fill: 0xFFFFFF
});
levelTxt.anchor.set(1, 0);
LK.gui.topRight.addChild(levelTxt);
function spawnBuilding() {
	var building = new Building();
	var spawnX = Math.random() * 1800 + 124;
	building.x = spawnX;
	building.y = 2500;
	buildings.push(building);
	game.addChild(building);
}
function spawnBoss() {
	boss = new Boss();
	boss.x = 1024;
	boss.y = 2500;
	game.addChild(boss);
}
function spawnBird() {
	var bird = new Bird();
	bird.x = bird.direction > 0 ? -50 : 2098;
	bird.y = Math.random() * 800 + 200;
	birds.push(bird);
	game.addChild(bird);
}
function spawnCloud() {
	var cloud = new Cloud();
	cloud.x = -150;
	cloud.y = Math.random() * 600 + 100;
	clouds.push(cloud);
	game.addChild(cloud);
}
function spawnWeatherParticle() {
	if (weatherType !== 'none') {
		var particle = new WeatherParticle();
		particle.init(weatherType);
		particle.x = Math.random() * 2048;
		particle.y = -20;
		weatherParticles.push(particle);
		game.addChild(particle);
	}
}
function updateSky() {
	skyBrightness += skyDirection * 0.002;
	if (skyBrightness <= 0.3) {
		skyBrightness = 0.3;
		skyDirection = 1;
	} else if (skyBrightness >= 1.0) {
		skyBrightness = 1.0;
		skyDirection = -1;
	}
	var skyColor = Math.floor(135 * skyBrightness) << 16 | Math.floor(206 * skyBrightness) << 8 | Math.floor(235 * skyBrightness);
	game.setBackgroundColor(skyColor);
}
function updateWeather() {
	weatherTimer++;
	if (weatherTimer >= weatherDuration) {
		// Change weather
		var weatherTypes = ['none', 'rain', 'snow'];
		weatherType = weatherTypes[Math.floor(Math.random() * 3)];
		weatherTimer = 0;
		weatherDuration = Math.random() * 1800 + 600; // 10-40 seconds
	}
}
function startLevel() {
	buildingsDestroyed = 0;
	levelTxt.setText('Level: ' + level);
	// Clear existing entities
	for (var i = buildings.length - 1; i >= 0; i--) {
		buildings[i].destroy();
	}
	buildings = [];
	for (var j = projectiles.length - 1; j >= 0; j--) {
		projectiles[j].destroy();
	}
	projectiles = [];
	if (boss) {
		boss.destroy();
		boss = null;
	}
	// Spawn initial buildings
	for (var k = 0; k < 3; k++) {
		LK.setTimeout(function () {
			spawnBuilding();
		}, k * 1000);
	}
}
// Start first level
startLevel();
// Game controls
game.down = function (x, y, obj) {
	monster.startCharging();
};
game.up = function (x, y, obj) {
	monster.jump();
};
game.move = function (x, y, obj) {
	// Move monster towards touch position
	if (x < monster.x) {
		monster.x -= monster.speed;
	} else if (x > monster.x) {
		monster.x += monster.speed;
	}
};
// Keyboard state tracking
var keys = {
	ArrowLeft: false,
	ArrowRight: false,
	Space: false
};
// Main game loop
game.update = function () {
	// Handle keyboard input (fallback to touch controls for mobile)
	// Note: Keyboard controls are not available in LK sandbox, using touch controls instead
	// Update score display
	scoreTxt.setText('Score: ' + LK.getScore());
	// Update health display
	healthTxt.setText('Health: ' + monster.health);
	// Update sky brightness
	updateSky();
	// Update weather
	updateWeather();
	// Spawn birds periodically
	birdSpawnTimer++;
	if (birdSpawnTimer >= 240) {
		// Every 4 seconds
		spawnBird();
		birdSpawnTimer = 0;
	}
	// Spawn clouds periodically
	cloudSpawnTimer++;
	if (cloudSpawnTimer >= 300) {
		// Every 5 seconds
		spawnCloud();
		cloudSpawnTimer = 0;
	}
	// Spawn weather particles
	if (weatherType !== 'none' && Math.random() < 0.3) {
		spawnWeatherParticle();
	}
	// Spawn new buildings periodically
	if (!boss && buildings.length < 5) {
		spawnTimer++;
		if (spawnTimer >= maxSpawnTimer) {
			spawnBuilding();
			spawnTimer = 0;
		}
	}
	// Check for boss spawn condition
	if (!boss && buildingsDestroyed >= 5 + level * 2) {
		spawnBoss();
	}
	// Remove destroyed projectiles
	for (var i = projectiles.length - 1; i >= 0; i--) {
		if (!projectiles[i].parent) {
			projectiles.splice(i, 1);
		}
	}
	// Remove destroyed buildings
	for (var j = buildings.length - 1; j >= 0; j--) {
		if (!buildings[j].parent) {
			buildings.splice(j, 1);
		}
	}
	// Remove destroyed birds
	for (var k = birds.length - 1; k >= 0; k--) {
		if (!birds[k].parent) {
			birds.splice(k, 1);
		}
	}
	// Remove destroyed clouds
	for (var l = clouds.length - 1; l >= 0; l--) {
		if (!clouds[l].parent) {
			clouds.splice(l, 1);
		}
	}
	// Remove destroyed weather particles
	for (var m = weatherParticles.length - 1; m >= 0; m--) {
		if (!weatherParticles[m].parent) {
			weatherParticles.splice(m, 1);
		}
	}
};

===================================================================
--- original.js
+++ change.js
@@ -5,8 +5,36 @@
 
 /**** 
 * Classes
 ****/ 
+var Bird = Container.expand(function () {
+	var self = Container.call(this);
+	var birdGraphics = self.attachAsset('bird', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.speed = Math.random() * 2 + 1;
+	self.direction = Math.random() > 0.5 ? 1 : -1;
+	self.flapTimer = 0;
+	self.update = function () {
+		self.x += self.speed * self.direction;
+		// Flap animation
+		self.flapTimer++;
+		if (self.flapTimer < 15) {
+			birdGraphics.scaleY = 0.8;
+		} else if (self.flapTimer < 30) {
+			birdGraphics.scaleY = 1.2;
+		} else {
+			self.flapTimer = 0;
+		}
+		// Remove if off screen
+		if (self.x < -50 || self.x > 2098) {
+			self.destroy();
+			birds.splice(birds.indexOf(self), 1);
+		}
+	};
+	return self;
+});
 var Boss = Container.expand(function () {
 	var self = Container.call(this);
 	var bossGraphics = self.attachAsset('boss', {
 		anchorX: 0.5,
@@ -35,11 +63,12 @@
 			monster.takeDamage(self.attackDamage);
 			LK.getSound('attack').play();
 			self.attackCooldown = self.maxAttackCooldown;
 		}
-		// Check if monster jumps on boss
+		// Check if monster jumps on boss - monster takes no damage when landing on boss
 		if (!self.lastIntersecting && currentIntersecting && monster.velocityY > 0) {
 			self.takeDamage(50);
+			// Monster doesn't take damage when landing on boss
 		}
 		self.lastIntersecting = currentIntersecting;
 	};
 	self.takeDamage = function (damage) {
@@ -89,8 +118,9 @@
 	};
 	self.stomp = function () {
 		LK.getSound('stomp').play();
 		LK.setScore(LK.getScore() + 10);
+		// Monster doesn't take damage when stomping on buildings
 		// Shrink building by one level
 		self.heightLevel--;
 		if (self.heightLevel <= 0) {
 			// Building destroyed
@@ -134,8 +164,27 @@
 		game.addChild(projectile);
 	};
 	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 = Math.random() * 0.5 + 0.2;
+	self.alpha = Math.random() * 0.4 + 0.6;
+	cloudGraphics.alpha = self.alpha;
+	self.update = function () {
+		self.x += self.speed;
+		// Remove if off screen
+		if (self.x > 2098 + 150) {
+			self.destroy();
+			clouds.splice(clouds.indexOf(self), 1);
+		}
+	};
+	return self;
+});
 var Monster = Container.expand(function () {
 	var self = Container.call(this);
 	var monsterGraphics = self.attachAsset('monster', {
 		anchorX: 0.5,
@@ -262,8 +311,42 @@
 		}
 	};
 	return self;
 });
+var WeatherParticle = Container.expand(function () {
+	var self = Container.call(this);
+	self.type = 'rain'; // 'rain' or 'snow'
+	self.speed = 0;
+	self.particleGraphics = null;
+	self.init = function (type) {
+		self.type = type;
+		if (type === 'rain') {
+			self.particleGraphics = self.attachAsset('rainDrop', {
+				anchorX: 0.5,
+				anchorY: 0.5
+			});
+			self.speed = Math.random() * 8 + 12;
+		} else {
+			self.particleGraphics = self.attachAsset('snowFlake', {
+				anchorX: 0.5,
+				anchorY: 0.5
+			});
+			self.speed = Math.random() * 3 + 2;
+		}
+	};
+	self.update = function () {
+		self.y += self.speed;
+		if (self.type === 'snow') {
+			self.x += Math.sin(self.y * 0.01) * 0.5;
+		}
+		// Remove if off screen
+		if (self.y > 2782) {
+			self.destroy();
+			weatherParticles.splice(weatherParticles.indexOf(self), 1);
+		}
+	};
+	return self;
+});
 
 /**** 
 * Initialize Game
 ****/ 
@@ -281,8 +364,18 @@
 var buildingsDestroyed = 0;
 var level = 1;
 var spawnTimer = 0;
 var maxSpawnTimer = 180;
+var birds = [];
+var clouds = [];
+var weatherParticles = [];
+var skyBrightness = 1.0;
+var skyDirection = -1;
+var weatherType = 'none'; // 'none', 'rain', 'snow'
+var weatherTimer = 0;
+var weatherDuration = 0;
+var birdSpawnTimer = 0;
+var cloudSpawnTimer = 0;
 // Create ground
 var ground = game.addChild(LK.getAsset('ground', {
 	anchorX: 0.5,
 	anchorY: 1.0,
@@ -329,8 +422,54 @@
 	boss.x = 1024;
 	boss.y = 2500;
 	game.addChild(boss);
 }
+function spawnBird() {
+	var bird = new Bird();
+	bird.x = bird.direction > 0 ? -50 : 2098;
+	bird.y = Math.random() * 800 + 200;
+	birds.push(bird);
+	game.addChild(bird);
+}
+function spawnCloud() {
+	var cloud = new Cloud();
+	cloud.x = -150;
+	cloud.y = Math.random() * 600 + 100;
+	clouds.push(cloud);
+	game.addChild(cloud);
+}
+function spawnWeatherParticle() {
+	if (weatherType !== 'none') {
+		var particle = new WeatherParticle();
+		particle.init(weatherType);
+		particle.x = Math.random() * 2048;
+		particle.y = -20;
+		weatherParticles.push(particle);
+		game.addChild(particle);
+	}
+}
+function updateSky() {
+	skyBrightness += skyDirection * 0.002;
+	if (skyBrightness <= 0.3) {
+		skyBrightness = 0.3;
+		skyDirection = 1;
+	} else if (skyBrightness >= 1.0) {
+		skyBrightness = 1.0;
+		skyDirection = -1;
+	}
+	var skyColor = Math.floor(135 * skyBrightness) << 16 | Math.floor(206 * skyBrightness) << 8 | Math.floor(235 * skyBrightness);
+	game.setBackgroundColor(skyColor);
+}
+function updateWeather() {
+	weatherTimer++;
+	if (weatherTimer >= weatherDuration) {
+		// Change weather
+		var weatherTypes = ['none', 'rain', 'snow'];
+		weatherType = weatherTypes[Math.floor(Math.random() * 3)];
+		weatherTimer = 0;
+		weatherDuration = Math.random() * 1800 + 600; // 10-40 seconds
+	}
+}
 function startLevel() {
 	buildingsDestroyed = 0;
 	levelTxt.setText('Level: ' + level);
 	// Clear existing entities
@@ -383,8 +522,30 @@
 	// Update score display
 	scoreTxt.setText('Score: ' + LK.getScore());
 	// Update health display
 	healthTxt.setText('Health: ' + monster.health);
+	// Update sky brightness
+	updateSky();
+	// Update weather
+	updateWeather();
+	// Spawn birds periodically
+	birdSpawnTimer++;
+	if (birdSpawnTimer >= 240) {
+		// Every 4 seconds
+		spawnBird();
+		birdSpawnTimer = 0;
+	}
+	// Spawn clouds periodically
+	cloudSpawnTimer++;
+	if (cloudSpawnTimer >= 300) {
+		// Every 5 seconds
+		spawnCloud();
+		cloudSpawnTimer = 0;
+	}
+	// Spawn weather particles
+	if (weatherType !== 'none' && Math.random() < 0.3) {
+		spawnWeatherParticle();
+	}
 	// Spawn new buildings periodically
 	if (!boss && buildings.length < 5) {
 		spawnTimer++;
 		if (spawnTimer >= maxSpawnTimer) {
@@ -407,5 +568,23 @@
 		if (!buildings[j].parent) {
 			buildings.splice(j, 1);
 		}
 	}
+	// Remove destroyed birds
+	for (var k = birds.length - 1; k >= 0; k--) {
+		if (!birds[k].parent) {
+			birds.splice(k, 1);
+		}
+	}
+	// Remove destroyed clouds
+	for (var l = clouds.length - 1; l >= 0; l--) {
+		if (!clouds[l].parent) {
+			clouds.splice(l, 1);
+		}
+	}
+	// Remove destroyed weather particles
+	for (var m = weatherParticles.length - 1; m >= 0; m--) {
+		if (!weatherParticles[m].parent) {
+			weatherParticles.splice(m, 1);
+		}
+	}
 };
\ No newline at end of file