/**** 
* Classes
****/ 
// Bird class: flies from right to left, above ground, destroys itself off screen
var Bird = Container.expand(function () {
	var self = Container.call(this);
	// Use 'gunes' asset for bird (placeholder, should be replaced with a bird asset if available)
	var birdSprite = self.attachAsset('gunes', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	birdSprite.width = 120;
	birdSprite.height = 90;
	birdSprite.tint = 0x888888;
	birdSprite.alpha = 0.92;
	self.speed = 10 + Math.random() * 4;
	self.update = function () {
		self.x -= self.speed;
		// Destroy if off screen
		if (self.lastX >= -200 && self.x < -200) {
			self.destroy();
		}
		self.lastX = self.x;
	};
	return self;
});
// Cactus class: moves left, destroys itself off screen
var Cactus = Container.expand(function () {
	var self = Container.call(this);
	// Attach cactus asset, anchor bottom left
	var cactusSprite = self.attachAsset('cactus', {
		anchorX: 0.5,
		anchorY: 1
	});
	self.speed = 7 + Math.random() * 2; // even slower speed for easier gameplay
	self.update = function () {
		self.x -= self.speed;
		// Destroy if off screen
		if (self.lastX >= -200 && self.x < -200) {
			self.destroy();
		}
		self.lastX = self.x;
	};
	return self;
});
// Cat class: handles jump, gravity, and collision
var Cat = Container.expand(function () {
	var self = Container.call(this);
	// Attach cat asset, anchor bottom left for ground logic
	var catSprite = self.attachAsset('cat', {
		anchorX: 0.5,
		anchorY: 1
	});
	// Cat physics
	self.y = 0;
	self.x = 0;
	self.vy = 0;
	self.isJumping = false;
	self.groundY = 0; // will be set after creation
	// Double jump state
	self.jumpCount = 0;
	self.maxJumps = 2;
	// Jump parameters
	self.jumpVelocity = -65;
	self.gravity = 4;
	// Update method for physics
	self.update = function () {
		if (self.isJumping) {
			// If we are hovering, do not apply gravity or move
			if (self.isHovering) {
				// Determine hover duration: 12 ticks (195ms) for first jump, 6 ticks (100ms) for others
				var hoverDuration = self.jumpCount === 1 ? 12 : 6;
				if (LK.ticks - self.hoverStartTick >= hoverDuration) {
					self.isHovering = false;
					// Resume falling, keep vy as 0 so gravity starts pulling down
					self.vy = 0;
				}
				// While hovering, do nothing else
				return;
			}
			// Normal jump/fall
			self.vy += self.gravity;
			self.y += self.vy;
			// At apex: vy just turned positive (was going up, now going down)
			if (!self.isHovering && self.vy > 0 && !self.hasHovered) {
				self.isHovering = true;
				self.hasHovered = true;
				self.hoverStartTick = LK.ticks;
				self.vy = 0; // Stop vertical movement during hover
				return;
			}
			// Land on ground
			if (self.y >= self.groundY) {
				self.y = self.groundY;
				self.vy = 0;
				self.isJumping = false;
				self.isHovering = false;
				self.hasHovered = false;
				self.jumpCount = 0; // Reset jump count on landing
			}
		}
	};
	// Jump method
	self.jump = function () {
		if (self.jumpCount < self.maxJumps) {
			self.isJumping = true;
			self.vy = self.jumpVelocity;
			self.isHovering = false;
			self.hasHovered = false;
			self.hoverStartTick = 0;
			self.jumpCount++;
		}
	};
	return self;
});
// Cloud class: moves left, destroys itself off screen
var Cloud = Container.expand(function () {
	var self = Container.call(this);
	// Use a white ellipse for the cloud
	var cloudSprite = self.attachAsset('centerCircle', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Randomize cloud size
	var scale = 1.2 + Math.random() * 1.2;
	cloudSprite.width = 320 * scale;
	cloudSprite.height = 120 * scale;
	cloudSprite.tint = 0xFFFFFF;
	cloudSprite.alpha = 0.7 + Math.random() * 0.2;
	self.speed = 1.5 + Math.random() * 1.2;
	self.update = function () {
		self.x -= self.speed;
		if (self.lastX >= -400 && self.x < -400) {
			self.destroy();
		}
		self.lastX = self.x;
	};
	return self;
});
// Gold class: moves left, destroys itself off screen, collectible by cat
var Gold = Container.expand(function () {
	var self = Container.call(this);
	// Attach gold asset, anchor center
	var goldSprite = self.attachAsset('ghost', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	goldSprite.width = 80;
	goldSprite.height = 80;
	self.speed = 7 + Math.random() * 2;
	self.collected = false;
	self.update = function () {
		self.x -= self.speed;
		// Destroy if off screen
		if (self.lastX >= -200 && self.x < -200) {
			self.destroy();
		}
		self.lastX = self.x;
	};
	return self;
});
// Sun class: static, top right
var Sun = Container.expand(function () {
	var self = Container.call(this);
	// Use a yellow ellipse for the sun
	var sunSprite = self.attachAsset('centerCircle', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	sunSprite.width = 260;
	sunSprite.height = 260;
	sunSprite.tint = 0xFFF700;
	sunSprite.alpha = 0.95;
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0xF7E9A0 // light sand yellow, desert-like
});

/**** 
* Game Code
****/ 
;
// --- GAME CODE ---
// Add a visible ground path to make the cat's running route more distinct
var groundPath = LK.getAsset('centerCircle', {
	anchorX: 0.5,
	anchorY: 0.5
});
groundPath.width = 2048;
groundPath.height = 120;
groundPath.x = 2048 / 2;
groundPath.y = GROUND_Y + 60; // center the path at ground level
groundPath.tint = 0xE0C97A; // a sandier, darker color for contrast
groundPath.alpha = 0.85;
game.addChild(groundPath);
// Add ground details: pebbles and stripes for more visual interest
var pebbleCount = 18;
for (var i = 0; i < pebbleCount; i++) {
	var pebble = LK.getAsset('centerCircle', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	pebble.width = 32 + Math.random() * 28;
	pebble.height = 18 + Math.random() * 12;
	pebble.x = 120 + Math.random() * (2048 - 240);
	pebble.y = GROUND_Y + 60 + (Math.random() - 0.5) * 60;
	pebble.tint = Math.random() > 0.5 ? 0xBCA86B : 0xD6C08B;
	pebble.alpha = 0.7 + Math.random() * 0.2;
	game.addChild(pebble);
}
// Add a few horizontal stripes to simulate track lines
for (var s = 0; s < 3; s++) {
	var stripe = LK.getAsset('centerCircle', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	stripe.width = 2048 * (0.7 + Math.random() * 0.2);
	stripe.height = 12 + Math.random() * 8;
	stripe.x = 2048 / 2;
	stripe.y = GROUND_Y + 30 + s * 28 + Math.random() * 10;
	stripe.tint = 0xC2B07A;
	stripe.alpha = 0.32 + Math.random() * 0.08;
	game.addChild(stripe);
}
// Sun and clouds
var sun;
var clouds = [];
var nextCloudTick = 0;
// Birds
var birds = [];
var nextBirdTick = 0;
// Game constants
var GROUND_Y = 2200; // y position of ground (bottom of screen minus margin)
var CAT_START_X = 400;
var CAT_START_Y = GROUND_Y;
var CACTUS_SPAWN_MIN = 40; // min frames between cacti (more frequent)
var CACTUS_SPAWN_MAX = 80; // max frames between cacti (more frequent)
// Game state
var cat;
var cacti = [];
var golds = [];
var score = 0;
var goldScore = 0;
var scoreTxt;
var goldScoreTxt;
var nextCactusTick = 0;
var nextGoldTick = 0;
var gameOver = false;
// Invulnerability timer: when > 0, cat is immune to cactus
var catInvulnerableTicks = 0;
// Speed multiplier for game progression
var speedMultiplier = 1;
var SPEED_MULTIPLIER_INCREMENT = 0.08; // how much to increase per score
var SPEED_MULTIPLIER_MAX = 3; // cap the speed increase
// Add score text to GUI
scoreTxt = new Text2('0', {
	size: 120,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Gold score text (smaller, right of score)
goldScoreTxt = new Text2('0', {
	size: 90,
	fill: 0xFFD700 // gold color
});
goldScoreTxt.anchor.set(0, 0);
goldScoreTxt.x = 120; // right of main score
goldScoreTxt.y = 20;
LK.gui.top.addChild(goldScoreTxt);
// Add sun (top right, margin from edge)
sun = new Sun();
sun.x = 2048 - 220;
sun.y = 220;
game.addChild(sun);
// Spawn a few initial clouds
for (var i = 0; i < 3; i++) {
	var cloud = new Cloud();
	cloud.x = 400 + Math.random() * 1400;
	cloud.y = 200 + Math.random() * 400;
	cloud.lastX = cloud.x;
	game.addChild(cloud);
	clouds.push(cloud);
}
nextCloudTick = 60 + Math.floor(Math.random() * 120);
// Create cat
cat = new Cat();
cat.x = CAT_START_X;
cat.y = CAT_START_Y;
cat.groundY = CAT_START_Y;
game.addChild(cat);
// Touch/click to jump
game.down = function (x, y, obj) {
	if (!gameOver) {
		cat.jump();
	}
	;
	// Update golds, check for collection
	for (var j = golds.length - 1; j >= 0; j--) {
		var gold = golds[j];
		gold.update();
		// Remove if off screen
		if (gold.x < -200) {
			gold.destroy();
			golds.splice(j, 1);
			continue;
		}
		// Collect gold: only trigger on first intersect and not already collected
		if (!gold.collected && cat.intersects(gold)) {
			gold.collected = true;
			goldScore++;
			goldScoreTxt.setText(goldScore);
			// Set invulnerability for 2 seconds (120 ticks)
			catInvulnerableTicks = 120;
			gold.destroy();
			golds.splice(j, 1);
			continue;
		}
	}
};
// Main update loop
game.update = function () {
	if (gameOver) return;
	// Decrease invulnerability timer if active
	if (catInvulnerableTicks > 0) {
		catInvulnerableTicks--;
	}
	// Update clouds and spawn new ones
	for (var i = clouds.length - 1; i >= 0; i--) {
		var cloud = clouds[i];
		cloud.update();
		if (cloud.x < -400) {
			cloud.destroy();
			clouds.splice(i, 1);
		}
	}
	if (nextCloudTick <= 0) {
		var cloud = new Cloud();
		cloud.x = 2048 + 200;
		cloud.y = 120 + Math.random() * 600;
		cloud.lastX = cloud.x;
		game.addChild(cloud);
		clouds.push(cloud);
		nextCloudTick = 60 + Math.floor(Math.random() * 120);
	} else {
		nextCloudTick--;
	}
	// Update birds and spawn new ones
	for (var i = birds.length - 1; i >= 0; i--) {
		var bird = birds[i];
		bird.update();
		if (bird.x < -200) {
			bird.destroy();
			birds.splice(i, 1);
		}
	}
	if (nextBirdTick <= 0) {
		// Spawn 2-3 birds at once, with more scattered (random) vertical and horizontal spacing
		var birdCount = 2 + Math.floor(Math.random() * 2); // 2 or 3 birds
		var minBirdY = GROUND_Y - 1850;
		var maxBirdY = GROUND_Y - 1350;
		if (minBirdY < 0) minBirdY = 0;
		if (maxBirdY < 0) maxBirdY = 0;
		var yRange = maxBirdY - minBirdY;
		var usedYs = [];
		for (var b = 0; b < birdCount; b++) {
			var bird = new Bird();
			// Scatter birds horizontally more
			bird.x = 2048 + 100 + Math.random() * 200 + b * 60 + Math.random() * 60;
			// Scatter birds vertically, allow overlap and more randomness
			var baseY = minBirdY + Math.random() * yRange;
			// Add more jitter, and avoid birds being too close vertically
			var jitterY = (Math.random() - 0.5) * 180;
			var finalY = baseY + jitterY;
			// Optionally, keep birds at least 120px apart vertically
			var minDist = 120;
			var attempts = 0;
			while (usedYs.some(function (y) {
				return Math.abs(y - finalY) < minDist;
			}) && attempts < 10) {
				finalY = minBirdY + Math.random() * yRange + (Math.random() - 0.5) * 180;
				attempts++;
			}
			usedYs.push(finalY);
			bird.y = finalY;
			bird.lastX = bird.x;
			// Apply speed multiplier to bird
			bird.speed = bird.speed * (0.8 + 0.4 * Math.random()) * speedMultiplier;
			game.addChild(bird);
			birds.push(bird);
		}
		// Bird group appears every 120-240 ticks
		nextBirdTick = 120 + Math.floor(Math.random() * 120);
	} else {
		nextBirdTick--;
	}
	// Update cat
	cat.update();
	// Spawn cactus
	if (nextCactusTick <= 0) {
		var cactus = new Cactus();
		cactus.x = 2048 + 100; // spawn just off right edge
		cactus.y = GROUND_Y;
		cactus.lastX = cactus.x;
		// Apply speed multiplier to cactus
		cactus.speed = cactus.speed * speedMultiplier;
		game.addChild(cactus);
		cacti.push(cactus);
		// Calculate minimum jump window: time to complete a jump (up, hover, down)
		// Estimate: jump up (abs(cat.jumpVelocity)/cat.gravity), hover (6 ticks), fall (same as up)
		// Total jump time in ticks
		var jumpUpTicks = Math.ceil(Math.abs(cat.jumpVelocity) / cat.gravity);
		var hoverTicks = 6;
		var jumpTotalTicks = jumpUpTicks + hoverTicks + jumpUpTicks;
		// Calculate cactus travel time from spawn to cat.x
		var cactusTravelDistance = 2048 + 100 - CAT_START_X;
		var avgCactusSpeed = (7 + 8.5) / 2 * speedMultiplier; // average speed, adjusted by multiplier
		if (avgCactusSpeed < 1) avgCactusSpeed = 1; // avoid divide by zero
		var cactusTravelTicks = cactusTravelDistance / avgCactusSpeed;
		// Minimum interval: enough time for cat to land and jump again before next cactus arrives
		// Add a small buffer (e.g. 10 ticks)
		var minInterval = Math.max(jumpTotalTicks + 10, 20);
		// Randomize interval, but always >= minInterval
		var spawnInterval = minInterval + Math.floor(Math.random() * 30);
		// Clamp to a minimum of 10 ticks for extreme speeds
		if (spawnInterval < 10) spawnInterval = 10;
		nextCactusTick = Math.floor(spawnInterval);
	} else {
		nextCactusTick--;
	}
	// Spawn gold
	if (nextGoldTick <= 0) {
		var gold = new Gold();
		gold.x = 2048 + 100;
		// Random Y: between ground and a bit above cat's jump apex
		var jumpApex = GROUND_Y + cat.jumpVelocity * (Math.abs(cat.jumpVelocity) / (2 * cat.gravity));
		var minY = GROUND_Y - 400;
		var maxY = GROUND_Y - 1000;
		if (maxY < 0) maxY = 0;
		gold.y = minY - Math.random() * (minY - maxY);
		gold.lastX = gold.x;
		gold.collected = false;
		gold.speed = gold.speed * speedMultiplier;
		game.addChild(gold);
		golds.push(gold);
		// Gold appears less frequently than cacti
		nextGoldTick = 80 + Math.floor(Math.random() * 120);
	} else {
		nextGoldTick--;
	}
	// Update golds, check for collection
	for (var j = golds.length - 1; j >= 0; j--) {
		var gold = golds[j];
		gold.update();
		// Remove if off screen
		if (gold.x < -200) {
			gold.destroy();
			golds.splice(j, 1);
			continue;
		}
		// Collect gold: only trigger on first intersect and not already collected
		if (!gold.collected && cat.intersects(gold)) {
			gold.collected = true;
			goldScore++;
			goldScoreTxt.setText(goldScore);
			gold.destroy();
			golds.splice(j, 1);
			continue;
		}
	}
	// Update cacti, check for collision and scoring
	for (var i = cacti.length - 1; i >= 0; i--) {
		var cactus = cacti[i];
		cactus.update();
		// Remove if off screen
		if (cactus.x < -200) {
			cactus.destroy();
			cacti.splice(i, 1);
			continue;
		}
		// Collision detection (only trigger on first intersect)
		if (!cactus.lastWasIntersecting && cat.intersects(cactus)) {
			// If not invulnerable, game over
			if (catInvulnerableTicks <= 0) {
				LK.effects.flashScreen(0xff0000, 800);
				LK.showGameOver();
				gameOver = true;
				return;
			}
			// If invulnerable, ignore collision (do nothing)
		}
		// Scoring: passed cactus (cat.x > cactus.x + cactus.width/2) and not already scored
		if (!cactus.scored && cat.x > cactus.x + cactus.width / 2) {
			score++;
			scoreTxt.setText(score);
			cactus.scored = true;
			// Increase speed multiplier, capped at max
			speedMultiplier += SPEED_MULTIPLIER_INCREMENT;
			if (speedMultiplier > SPEED_MULTIPLIER_MAX) speedMultiplier = SPEED_MULTIPLIER_MAX;
			// After level 30, allow 3 jumps
			if (score >= 30) {
				cat.maxJumps = 3;
			}
		}
		cactus.lastWasIntersecting = cat.intersects(cactus);
	}
};

===================================================================
--- original.js
+++ change.js
@@ -250,8 +250,10 @@
 var goldScoreTxt;
 var nextCactusTick = 0;
 var nextGoldTick = 0;
 var gameOver = false;
+// Invulnerability timer: when > 0, cat is immune to cactus
+var catInvulnerableTicks = 0;
 // Speed multiplier for game progression
 var speedMultiplier = 1;
 var SPEED_MULTIPLIER_INCREMENT = 0.08; // how much to increase per score
 var SPEED_MULTIPLIER_MAX = 3; // cap the speed increase
@@ -312,8 +314,10 @@
 		if (!gold.collected && cat.intersects(gold)) {
 			gold.collected = true;
 			goldScore++;
 			goldScoreTxt.setText(goldScore);
+			// Set invulnerability for 2 seconds (120 ticks)
+			catInvulnerableTicks = 120;
 			gold.destroy();
 			golds.splice(j, 1);
 			continue;
 		}
@@ -321,8 +325,12 @@
 };
 // Main update loop
 game.update = function () {
 	if (gameOver) return;
+	// Decrease invulnerability timer if active
+	if (catInvulnerableTicks > 0) {
+		catInvulnerableTicks--;
+	}
 	// Update clouds and spawn new ones
 	for (var i = clouds.length - 1; i >= 0; i--) {
 		var cloud = clouds[i];
 		cloud.update();
@@ -476,13 +484,16 @@
 			continue;
 		}
 		// Collision detection (only trigger on first intersect)
 		if (!cactus.lastWasIntersecting && cat.intersects(cactus)) {
-			// Game over
-			LK.effects.flashScreen(0xff0000, 800);
-			LK.showGameOver();
-			gameOver = true;
-			return;
+			// If not invulnerable, game over
+			if (catInvulnerableTicks <= 0) {
+				LK.effects.flashScreen(0xff0000, 800);
+				LK.showGameOver();
+				gameOver = true;
+				return;
+			}
+			// If invulnerable, ignore collision (do nothing)
 		}
 		// Scoring: passed cactus (cat.x > cactus.x + cactus.width/2) and not already scored
 		if (!cactus.scored && cat.x > cactus.x + cactus.width / 2) {
 			score++;