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

/**** 
* Classes
****/ 
// Item class for all falling items
var Item = Container.expand(function () {
	var self = Container.call(this);
	// Asset id and score are set on creation
	self.assetId = 'item_basic';
	self.scoreValue = 1;
	self.isBad = false; // true for bomb/spike
	self.isTapped = false;
	// Attach asset
	var itemGfx = self.attachAsset(self.assetId, {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Set up item visuals
	self.setType = function (type) {
		// type: {assetId, scoreValue, isBad}
		self.assetId = type.assetId;
		self.scoreValue = type.scoreValue;
		self.isBad = type.isBad;
		// Remove old asset if any
		if (itemGfx && itemGfx.parent) itemGfx.parent.removeChild(itemGfx);
		itemGfx = self.attachAsset(self.assetId, {
			anchorX: 0.5,
			anchorY: 0.5
		});
		// For bomb/spike, add a little rotation
		if (self.isBad) {
			itemGfx.rotation = Math.PI / 8 * (Math.random() > 0.5 ? 1 : -1);
		}
	};
	// Called when tapped
	self.onTap = function () {
		if (self.isTapped) return;
		self.isTapped = true;
		// No pop effect
	};
	// Called every tick
	self.update = function () {
		// Movement handled in game loop
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x181818
});

/**** 
* Game Code
****/ 
// Music
// Sounds
// Pop effect
// Bad items
// Good items
// Item types
var ITEM_TYPES = [{
	assetId: 'item_basic',
	scoreValue: 1,
	isBad: false,
	weight: 60
}, {
	assetId: 'item_rare',
	scoreValue: 3,
	isBad: false,
	weight: 20
}, {
	assetId: 'item_legend',
	scoreValue: 7,
	isBad: false,
	weight: 5
}, {
	assetId: 'item_bomb',
	scoreValue: 0,
	isBad: true,
	weight: 10
}, {
	assetId: 'item_spike',
	scoreValue: 0,
	isBad: true,
	weight: 5
}];
// Weighted random selection
function pickItemType() {
	var total = 0;
	for (var i = 0; i < ITEM_TYPES.length; i++) total += ITEM_TYPES[i].weight;
	var r = Math.random() * total;
	var acc = 0;
	for (var i = 0; i < ITEM_TYPES.length; i++) {
		acc += ITEM_TYPES[i].weight;
		if (r < acc) return ITEM_TYPES[i];
	}
	return ITEM_TYPES[0];
}
// Game state
var items = [];
var lives = 3;
var score = 0;
var spawnInterval = 1000; // ms
var minSpawnInterval = 350;
var spawnTimer = null;
var itemFallSpeed = 7; // px per frame
var itemSpeedInc = 0.15;
var itemSpawnDec = 30;
var lastTapTime = 0;
// Difficulty menu
var difficultyMenu = null;
var difficultySettings = {
	Easy: {
		lives: 5,
		spawnInterval: 1200,
		minSpawnInterval: 500,
		itemFallSpeed: 5,
		itemSpeedInc: 0.10,
		itemSpawnDec: 18
	},
	Normal: {
		lives: 3,
		spawnInterval: 1000,
		minSpawnInterval: 350,
		itemFallSpeed: 7,
		itemSpeedInc: 0.15,
		itemSpawnDec: 30
	},
	Hard: {
		lives: 2,
		spawnInterval: 800,
		minSpawnInterval: 200,
		itemFallSpeed: 10,
		itemSpeedInc: 0.22,
		itemSpawnDec: 45
	}
};
var selectedDifficulty = "Normal";
// Show difficulty menu at game start
function showDifficultyMenu() {
	if (difficultyMenu && difficultyMenu.parent) difficultyMenu.parent.removeChild(difficultyMenu);
	difficultyMenu = new Container();
	// Background overlay
	var bg = LK.getAsset('item_basic', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	bg.width = 900;
	bg.height = 900;
	bg.alpha = 0.92;
	bg.x = 2048 / 2;
	bg.y = 2732 / 2;
	difficultyMenu.addChild(bg);
	// Title
	var title = new Text2("Select Difficulty", {
		size: 120,
		fill: "#fff"
	});
	title.anchor.set(0.5, 0);
	title.x = 2048 / 2;
	title.y = 2732 / 2 - 320;
	difficultyMenu.addChild(title);
	// Buttons
	var btnY = 2732 / 2 - 80;
	var btns = ["Easy", "Normal", "Hard"];
	for (var i = 0; i < btns.length; i++) {
		(function (idx) {
			var diff = btns[idx];
			var btn = LK.getAsset('item_legend', {
				anchorX: 0.5,
				anchorY: 0.5
			});
			btn.width = 520;
			btn.height = 160;
			btn.x = 2048 / 2;
			btn.y = btnY + idx * 200;
			difficultyMenu.addChild(btn);
			var label = new Text2(diff, {
				size: 90,
				fill: "#222"
			});
			label.anchor.set(0.5, 0.5);
			label.x = btn.x;
			label.y = btn.y;
			difficultyMenu.addChild(label);
			btn.interactive = true;
			btn.down = function (x, y, obj) {
				selectDifficulty(diff);
			};
		})(i);
	}
	// Add to game
	game.addChild(difficultyMenu);
	// Pause spawn
	if (spawnTimer) LK.clearInterval(spawnTimer);
}
// Set difficulty and start game
function selectDifficulty(diff) {
	selectedDifficulty = diff;
	var s = difficultySettings[diff];
	lives = s.lives;
	spawnInterval = s.spawnInterval;
	minSpawnInterval = s.minSpawnInterval;
	itemFallSpeed = s.itemFallSpeed;
	itemSpeedInc = s.itemSpeedInc;
	itemSpawnDec = s.itemSpawnDec;
	updateLives();
	score = 0;
	scoreTxt.setText(score);
	if (difficultyMenu && difficultyMenu.parent) difficultyMenu.parent.removeChild(difficultyMenu);
	startSpawnTimer();
}
// Show menu at game start
showDifficultyMenu();
// GUI
var scoreTxt = new Text2('0', {
	size: 120,
	fill: "#fff"
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
var livesTxt = new Text2('♥♥♥', {
	size: 90,
	fill: 0xFF5252
});
livesTxt.anchor.set(1, 0);
livesTxt.x = -40; // right padding
LK.gui.topRight.addChild(livesTxt);
// Prevent elements in top left 100x100
// (No elements added to gui.topLeft or at (0,0))
// Music
LK.playMusic('bgmusic');
// Spawn a new item
function spawnItem() {
	var type = pickItemType();
	var item = new Item();
	item.setType(type);
	// Random X, avoid edges
	var margin = 120;
	var x = margin + Math.random() * (2048 - 2 * margin);
	item.x = x;
	item.y = -100;
	// For touch detection
	item.width = LK.getAsset(type.assetId, {
		anchorX: 0.5,
		anchorY: 0.5
	}).width;
	item.height = LK.getAsset(type.assetId, {
		anchorX: 0.5,
		anchorY: 0.5
	}).height;
	// Add to game
	game.addChild(item);
	items.push(item);
}
// Update lives display
function updateLives() {
	var s = '';
	for (var i = 0; i < lives; i++) s += '♥';
	livesTxt.setText(s);
}
// Handle tap
function handleTap(x, y, obj) {
	// Find topmost item under tap
	for (var i = items.length - 1; i >= 0; i--) {
		var item = items[i];
		// Simple bounding box check
		var dx = x - item.x;
		var dy = y - item.y;
		var w = item.width / 2;
		var h = item.height / 2;
		if (dx * dx / (w * w) + dy * dy / (h * h) <= 1.1) {
			// Tapped this item
			if (item.isTapped) continue;
			item.onTap();
			if (item.isBad) {
				// Lose a life
				lives--;
				updateLives();
				LK.getSound('bad').play();
				LK.effects.flashScreen(0xff0000, 350);
				if (lives <= 0) {
					LK.getSound('lose').play();
					LK.showGameOver();
					return;
				}
			} else {
				// Score!
				score += item.scoreValue;
				LK.setScore(score);
				scoreTxt.setText(score);
				LK.getSound('score').play();
				// Animate item
				tween(item, {
					scaleX: 1.3,
					scaleY: 1.3,
					alpha: 0
				}, {
					duration: 220,
					easing: tween.easeOut,
					onFinish: function onFinish() {
						if (item.parent) item.parent.removeChild(item);
					}
				});
			}
			// Remove item from array
			items.splice(i, 1);
			break;
		}
	}
}
// Game move/tap handler
game.down = function (x, y, obj) {
	handleTap(x, y, obj);
};
// Main update loop
game.update = function () {
	// Move items
	for (var i = items.length - 1; i >= 0; i--) {
		var item = items[i];
		item.y += itemFallSpeed;
		// If not tapped and off screen
		if (!item.isTapped && item.y > 2732 + 100) {
			// If good item missed, lose a life
			if (!item.isBad) {
				lives--;
				updateLives();
				LK.getSound('life').play();
				LK.effects.flashScreen(0xff9800, 250);
				if (lives <= 0) {
					LK.getSound('lose').play();
					LK.showGameOver();
					return;
				}
			}
			// Remove from game
			if (item.parent) item.parent.removeChild(item);
			items.splice(i, 1);
		}
	}
	// Difficulty ramp: every 10 points, increase speed and spawn rate
	var level = Math.floor(score / 10);
	var targetSpeed = 7 + level * itemSpeedInc;
	if (itemFallSpeed < targetSpeed) itemFallSpeed += 0.02;
	var targetInterval = Math.max(minSpawnInterval, 1000 - level * itemSpawnDec);
	if (spawnInterval > targetInterval) spawnInterval -= 1.5;
};
// Spawn timer
function startSpawnTimer() {
	if (spawnTimer) LK.clearInterval(spawnTimer);
	spawnTimer = LK.setInterval(function () {
		spawnItem();
		// Adjust interval
		LK.clearInterval(spawnTimer);
		startSpawnTimer();
	}, spawnInterval);
}
startSpawnTimer();
// Reset on game over
LK.on('gameover', function () {
	// Clean up
	for (var i = 0; i < items.length; i++) {
		if (items[i].parent) items[i].parent.removeChild(items[i]);
	}
	items = [];
	// Show difficulty menu again
	showDifficultyMenu();
	LK.playMusic('bgmusic');
});
// Reset on win (not used, but for completeness)
LK.on('youwin', function () {
	for (var i = 0; i < items.length; i++) {
		if (items[i].parent) items[i].parent.removeChild(items[i]);
	}
	items = [];
	showDifficultyMenu();
	LK.playMusic('bgmusic');
});

===================================================================
--- original.js
+++ change.js
@@ -113,8 +113,113 @@
 var itemFallSpeed = 7; // px per frame
 var itemSpeedInc = 0.15;
 var itemSpawnDec = 30;
 var lastTapTime = 0;
+// Difficulty menu
+var difficultyMenu = null;
+var difficultySettings = {
+	Easy: {
+		lives: 5,
+		spawnInterval: 1200,
+		minSpawnInterval: 500,
+		itemFallSpeed: 5,
+		itemSpeedInc: 0.10,
+		itemSpawnDec: 18
+	},
+	Normal: {
+		lives: 3,
+		spawnInterval: 1000,
+		minSpawnInterval: 350,
+		itemFallSpeed: 7,
+		itemSpeedInc: 0.15,
+		itemSpawnDec: 30
+	},
+	Hard: {
+		lives: 2,
+		spawnInterval: 800,
+		minSpawnInterval: 200,
+		itemFallSpeed: 10,
+		itemSpeedInc: 0.22,
+		itemSpawnDec: 45
+	}
+};
+var selectedDifficulty = "Normal";
+// Show difficulty menu at game start
+function showDifficultyMenu() {
+	if (difficultyMenu && difficultyMenu.parent) difficultyMenu.parent.removeChild(difficultyMenu);
+	difficultyMenu = new Container();
+	// Background overlay
+	var bg = LK.getAsset('item_basic', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	bg.width = 900;
+	bg.height = 900;
+	bg.alpha = 0.92;
+	bg.x = 2048 / 2;
+	bg.y = 2732 / 2;
+	difficultyMenu.addChild(bg);
+	// Title
+	var title = new Text2("Select Difficulty", {
+		size: 120,
+		fill: "#fff"
+	});
+	title.anchor.set(0.5, 0);
+	title.x = 2048 / 2;
+	title.y = 2732 / 2 - 320;
+	difficultyMenu.addChild(title);
+	// Buttons
+	var btnY = 2732 / 2 - 80;
+	var btns = ["Easy", "Normal", "Hard"];
+	for (var i = 0; i < btns.length; i++) {
+		(function (idx) {
+			var diff = btns[idx];
+			var btn = LK.getAsset('item_legend', {
+				anchorX: 0.5,
+				anchorY: 0.5
+			});
+			btn.width = 520;
+			btn.height = 160;
+			btn.x = 2048 / 2;
+			btn.y = btnY + idx * 200;
+			difficultyMenu.addChild(btn);
+			var label = new Text2(diff, {
+				size: 90,
+				fill: "#222"
+			});
+			label.anchor.set(0.5, 0.5);
+			label.x = btn.x;
+			label.y = btn.y;
+			difficultyMenu.addChild(label);
+			btn.interactive = true;
+			btn.down = function (x, y, obj) {
+				selectDifficulty(diff);
+			};
+		})(i);
+	}
+	// Add to game
+	game.addChild(difficultyMenu);
+	// Pause spawn
+	if (spawnTimer) LK.clearInterval(spawnTimer);
+}
+// Set difficulty and start game
+function selectDifficulty(diff) {
+	selectedDifficulty = diff;
+	var s = difficultySettings[diff];
+	lives = s.lives;
+	spawnInterval = s.spawnInterval;
+	minSpawnInterval = s.minSpawnInterval;
+	itemFallSpeed = s.itemFallSpeed;
+	itemSpeedInc = s.itemSpeedInc;
+	itemSpawnDec = s.itemSpawnDec;
+	updateLives();
+	score = 0;
+	scoreTxt.setText(score);
+	if (difficultyMenu && difficultyMenu.parent) difficultyMenu.parent.removeChild(difficultyMenu);
+	startSpawnTimer();
+}
+// Show menu at game start
+showDifficultyMenu();
 // GUI
 var scoreTxt = new Text2('0', {
 	size: 120,
 	fill: "#fff"
@@ -264,28 +369,17 @@
 	for (var i = 0; i < items.length; i++) {
 		if (items[i].parent) items[i].parent.removeChild(items[i]);
 	}
 	items = [];
-	lives = 3;
-	score = 0;
-	spawnInterval = 1000;
-	itemFallSpeed = 7;
-	updateLives();
-	scoreTxt.setText(score);
-	startSpawnTimer();
+	// Show difficulty menu again
+	showDifficultyMenu();
 	LK.playMusic('bgmusic');
 });
 // Reset on win (not used, but for completeness)
 LK.on('youwin', function () {
 	for (var i = 0; i < items.length; i++) {
 		if (items[i].parent) items[i].parent.removeChild(items[i]);
 	}
 	items = [];
-	lives = 3;
-	score = 0;
-	spawnInterval = 1000;
-	itemFallSpeed = 7;
-	updateLives();
-	scoreTxt.setText(score);
-	startSpawnTimer();
+	showDifficultyMenu();
 	LK.playMusic('bgmusic');
 });
\ No newline at end of file