===================================================================
--- original.js
+++ change.js
@@ -1,6 +1,775 @@
-/****
+/**** 
+* Plugins
+****/ 
+var tween = LK.import("@upit/tween.v1");
+
+/**** 
+* Classes
+****/ 
+// Burrower monster
+var Burrower = Container.expand(function () {
+	var self = Container.call(this);
+	var burrowerGfx = self.attachAsset('burrower', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.radius = burrowerGfx.width / 2;
+	self.speed = 10;
+	self.hp = 1;
+	self.type = 'burrower';
+	self.burrowTimer = 0;
+	self.burrowInterval = 90 + Math.floor(Math.random() * 60);
+	self.burrowed = false;
+	self.update = function () {
+		if (self.burrowed) {
+			self.burrowTimer--;
+			if (self.burrowTimer <= 0) {
+				// Unburrow
+				self.burrowed = false;
+				burrowerGfx.alpha = 1;
+				self.burrowTimer = self.burrowInterval;
+			}
+			// Move fast toward hero
+			var dx = hero.x - self.x;
+			var dy = hero.y - self.y;
+			var d = Math.sqrt(dx * dx + dy * dy);
+			if (d > 0.1) {
+				self.x += dx / d * (self.speed * 2.2);
+				self.y += dy / d * (self.speed * 2.2);
+			}
+		} else {
+			self.burrowTimer--;
+			if (self.burrowTimer <= 0) {
+				// Burrow
+				self.burrowed = true;
+				burrowerGfx.alpha = 0.3;
+				self.burrowTimer = 36 + Math.floor(Math.random() * 24);
+			}
+			// Move toward hero
+			var dx = hero.x - self.x;
+			var dy = hero.y - self.y;
+			var d = Math.sqrt(dx * dx + dy * dy);
+			if (d > 0.1) {
+				self.x += dx / d * self.speed;
+				self.y += dy / d * self.speed;
+			}
+		}
+	};
+	self.flash = function () {
+		tween(burrowerGfx, {
+			alpha: 0.1
+		}, {
+			duration: 40,
+			onFinish: function onFinish() {
+				tween(burrowerGfx, {
+					alpha: self.burrowed ? 0.3 : 1
+				}, {
+					duration: 40
+				});
+			}
+		});
+	};
+	return self;
+});
+// Chaser monster
+var Chaser = Container.expand(function () {
+	var self = Container.call(this);
+	var chaserGfx = self.attachAsset('chaser', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.radius = chaserGfx.width / 2;
+	self.speed = 7.5;
+	self.hp = 2;
+	self.type = 'chaser';
+	self.update = function () {
+		// Move toward hero
+		var dx = hero.x - self.x;
+		var dy = hero.y - self.y;
+		var d = Math.sqrt(dx * dx + dy * dy);
+		if (d > 0.1) {
+			self.x += dx / d * self.speed;
+			self.y += dy / d * self.speed;
+		}
+	};
+	self.flash = function () {
+		tween(chaserGfx, {
+			alpha: 0.3
+		}, {
+			duration: 60,
+			onFinish: function onFinish() {
+				tween(chaserGfx, {
+					alpha: 1
+				}, {
+					duration: 60
+				});
+			}
+		});
+	};
+	return self;
+});
+// Gold coin
+var Gold = Container.expand(function () {
+	var self = Container.call(this);
+	var goldGfx = self.attachAsset('gold', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.radius = goldGfx.width / 2;
+	self.vx = 0;
+	self.vy = 0;
+	self.update = function () {
+		self.x += self.vx;
+		self.y += self.vy;
+		// Slow down
+		self.vx *= 0.92;
+		self.vy *= 0.92;
+	};
+	return self;
+});
+// Hero class
+var Hero = Container.expand(function () {
+	var self = Container.call(this);
+	var heroGfx = self.attachAsset('hero', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.radius = heroGfx.width / 2;
+	self.speed = 22;
+	self.shootCooldown = 0;
+	self.shootInterval = 18; // frames
+	self.invuln = 0;
+	self.hp = 3;
+	self.update = function () {
+		if (self.shootCooldown > 0) self.shootCooldown--;
+		if (self.invuln > 0) self.invuln--;
+	};
+	// Flash when hit
+	self.flash = function () {
+		tween(heroGfx, {
+			alpha: 0.3
+		}, {
+			duration: 80,
+			onFinish: function onFinish() {
+				tween(heroGfx, {
+					alpha: 1
+				}, {
+					duration: 80
+				});
+			}
+		});
+	};
+	return self;
+});
+// Hero bullet
+var HeroBullet = Container.expand(function () {
+	var self = Container.call(this);
+	var bulletGfx = self.attachAsset('herobullet', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.radius = bulletGfx.width / 2;
+	self.speed = 38;
+	self.dirX = 0;
+	self.dirY = -1;
+	self.damage = 1;
+	self.update = function () {
+		self.x += self.dirX * self.speed;
+		self.y += self.dirY * self.speed;
+	};
+	return self;
+});
+// Monster bullet (spit)
+var MonsterBullet = Container.expand(function () {
+	var self = Container.call(this);
+	var bulletGfx = self.attachAsset('herobullet', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	bulletGfx.tint = 0x7cfd3a;
+	self.radius = bulletGfx.width / 2;
+	self.speed = 16;
+	self.dirX = 0;
+	self.dirY = 1;
+	self.damage = 1;
+	self.update = function () {
+		self.x += self.dirX * self.speed;
+		self.y += self.dirY * self.speed;
+	};
+	return self;
+});
+// Spitter monster
+var Spitter = Container.expand(function () {
+	var self = Container.call(this);
+	var spitterGfx = self.attachAsset('spitter', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.radius = spitterGfx.width / 2;
+	self.speed = 4.5;
+	self.hp = 2;
+	self.type = 'spitter';
+	self.shootCooldown = 0;
+	self.shootInterval = 60 + Math.floor(Math.random() * 30);
+	self.update = function () {
+		// Keep distance from hero, shoot
+		var dx = hero.x - self.x;
+		var dy = hero.y - self.y;
+		var d = Math.sqrt(dx * dx + dy * dy);
+		if (d > 400) {
+			self.x += dx / d * self.speed;
+			self.y += dy / d * self.speed;
+		} else if (d < 320) {
+			self.x -= dx / d * self.speed;
+			self.y -= dy / d * self.speed;
+		}
+		if (self.shootCooldown > 0) self.shootCooldown--;else {
+			// Spit at hero
+			var spit = new MonsterBullet();
+			spit.x = self.x;
+			spit.y = self.y;
+			var tx = hero.x - self.x;
+			var ty = hero.y - self.y;
+			var td = Math.sqrt(tx * tx + ty * ty);
+			spit.dirX = td > 0.1 ? tx / td : 0;
+			spit.dirY = td > 0.1 ? ty / td : 0;
+			spit.speed = 16;
+			spit.radius = 32;
+			monsterBullets.push(spit);
+			game.addChild(spit);
+			self.shootCooldown = self.shootInterval;
+		}
+	};
+	self.flash = function () {
+		tween(spitterGfx, {
+			alpha: 0.3
+		}, {
+			duration: 60,
+			onFinish: function onFinish() {
+				tween(spitterGfx, {
+					alpha: 1
+				}, {
+					duration: 60
+				});
+			}
+		});
+	};
+	return self;
+});
+
+/**** 
 * Initialize Game
-****/
+****/ 
 var game = new LK.Game({
-	backgroundColor: 0x000000
+	backgroundColor: 0x181818
+});
+
+/**** 
+* Game Code
+****/ 
+// Sound effects
+// Store button highlight
+// Store button background
+// Gold coin
+// Hero bullet
+// Burrower monster
+// Spitter monster
+// Chaser monster
+// Hero
+// Global variables
+var hero = new Hero();
+var heroBullets = [];
+var monsters = [];
+var monsterBullets = [];
+var golds = [];
+var gold = 0;
+var storeBtns = [];
+var passives = [];
+var availablePassives = [{
+	id: 'firerate',
+	name: 'Rapid Fire',
+	desc: 'Shoot much faster.',
+	apply: function apply() {
+		hero.shootInterval = Math.max(6, hero.shootInterval - 8);
+	}
+}, {
+	id: 'pierce',
+	name: 'Piercing Shots',
+	desc: 'Bullets pierce through 1 extra enemy.',
+	apply: function apply() {
+		passives.push({
+			id: 'pierce',
+			stacks: 1
+		});
+	}
+}, {
+	id: 'lifesteal',
+	name: 'Lifesteal',
+	desc: 'Gain 1 HP every 8 gold picked up.',
+	apply: function apply() {
+		passives.push({
+			id: 'lifesteal',
+			stacks: 1,
+			counter: 0
+		});
+	}
+}, {
+	id: 'spread',
+	name: 'Spread Shot',
+	desc: 'Shoot 3 bullets in a spread.',
+	apply: function apply() {
+		passives.push({
+			id: 'spread',
+			stacks: 1
+		});
+	}
+}, {
+	id: 'regen',
+	name: 'Regeneration',
+	desc: 'Regenerate 1 HP every 12 seconds.',
+	apply: function apply() {
+		passives.push({
+			id: 'regen',
+			stacks: 1,
+			timer: 0
+		});
+	}
+}, {
+	id: 'speed',
+	name: 'Speed Boost',
+	desc: 'Move much faster.',
+	apply: function apply() {
+		hero.speed += 7;
+	}
+}, {
+	id: 'bigshot',
+	name: 'Big Bullets',
+	desc: 'Bullets are much larger.',
+	apply: function apply() {
+		passives.push({
+			id: 'bigshot',
+			stacks: 1
+		});
+	}
+}, {
+	id: 'goldboost',
+	name: 'Gold Magnet',
+	desc: 'Gold is attracted to you.',
+	apply: function apply() {
+		passives.push({
+			id: 'goldboost',
+			stacks: 1
+		});
+	}
+}, {
+	id: 'maxhp',
+	name: 'Max HP Up',
+	desc: 'Increase max HP by 1.',
+	apply: function apply() {
+		hero.hp++;
+	}
+}];
+// Store state
+var storeChoices = [];
+function getRandomPassive(excludeIds) {
+	var pool = [];
+	for (var i = 0; i < availablePassives.length; ++i) {
+		var id = availablePassives[i].id;
+		var already = false;
+		for (var j = 0; j < excludeIds.length; ++j) {
+			if (excludeIds[j] === id) {
+				already = true;
+				break;
+			}
+		}
+		if (!already) pool.push(availablePassives[i]);
+	}
+	if (pool.length === 0) pool = availablePassives;
+	return pool[Math.floor(Math.random() * pool.length)];
+}
+function rerollStore() {
+	storeChoices = [];
+	var exclude = [];
+	for (var i = 0; i < 3; ++i) {
+		var p = getRandomPassive(exclude);
+		storeChoices.push(p);
+		exclude.push(p.id);
+	}
+	updateStoreBtns();
+}
+function updateStoreBtns() {
+	for (var i = 0; i < storeBtns.length; ++i) {
+		var btn = storeBtns[i];
+		var p = storeChoices[i];
+		btn.passive = p;
+		btn.txt.setText(p.name);
+		btn.desc.setText(p.desc);
+		btn.price.setText("5");
+	}
+}
+// GUI
+var goldTxt = new Text2('0', {
+	size: 90,
+	fill: 0xFFE066
+});
+goldTxt.anchor.set(1, 0);
+LK.gui.topRight.addChild(goldTxt);
+var hpTxt = new Text2('❤❤❤', {
+	size: 90,
+	fill: 0xFF3A3A
+});
+hpTxt.anchor.set(0, 0);
+LK.gui.top.addChild(hpTxt);
+// Store buttons (top right, below gold)
+for (var i = 0; i < 3; ++i) {
+	var btn = new Container();
+	var bg = btn.attachAsset('storebtn', {
+		anchorX: 1,
+		anchorY: 0
+	});
+	btn.x = 2048 - 40;
+	btn.y = 160 + i * 140;
+	btn.txt = new Text2('', {
+		size: 54,
+		fill: 0xFFE066
+	});
+	btn.txt.anchor.set(1, 0);
+	btn.txt.x = 380;
+	btn.txt.y = 12;
+	btn.addChild(btn.txt);
+	btn.desc = new Text2('', {
+		size: 36,
+		fill: 0xCCCCCC
+	});
+	btn.desc.anchor.set(1, 0);
+	btn.desc.x = 380;
+	btn.desc.y = 62;
+	btn.addChild(btn.desc);
+	btn.price = new Text2('5', {
+		size: 48,
+		fill: 0xFFD700
+	});
+	btn.price.anchor.set(0, 0);
+	btn.price.x = 20;
+	btn.price.y = 30;
+	btn.addChild(btn.price);
+	btn.index = i;
+	storeBtns.push(btn);
+	game.addChild(btn);
+}
+// Place hero in center
+hero.x = 2048 / 2;
+hero.y = 2732 / 2;
+game.addChild(hero);
+// Initial monsters
+function spawnMonster() {
+	var edge = Math.floor(Math.random() * 4);
+	var x, y;
+	if (edge === 0) {
+		// top
+		x = 200 + Math.random() * (2048 - 400);
+		y = -80;
+	} else if (edge === 1) {
+		// bottom
+		x = 200 + Math.random() * (2048 - 400);
+		y = 2732 + 80;
+	} else if (edge === 2) {
+		// left
+		x = -80;
+		y = 200 + Math.random() * (2732 - 400);
+	} else {
+		// right
+		x = 2048 + 80;
+		y = 200 + Math.random() * (2732 - 400);
+	}
+	var t = Math.random();
+	var m;
+	if (t < 0.4) m = new Chaser();else if (t < 0.7) m = new Spitter();else m = new Burrower();
+	m.x = x;
+	m.y = y;
+	monsters.push(m);
+	game.addChild(m);
+}
+for (var i = 0; i < 5; ++i) spawnMonster();
+// Store logic
+rerollStore();
+// Dragging
+var dragNode = null;
+function handleMove(x, y, obj) {
+	if (dragNode) {
+		// Clamp to screen
+		var r = hero.radius;
+		dragNode.x = Math.max(r, Math.min(2048 - r, x));
+		dragNode.y = Math.max(r, Math.min(2732 - r, y));
+	}
+}
+game.move = handleMove;
+game.down = function (x, y, obj) {
+	// Check store buttons first
+	for (var i = 0; i < storeBtns.length; ++i) {
+		var btn = storeBtns[i];
+		var bx = btn.x - 420,
+			by = btn.y,
+			bw = 420,
+			bh = 120;
+		if (x >= bx && x <= bx + bw && y >= by && y <= by + bh) {
+			// Buy
+			if (gold >= 5) {
+				gold -= 5;
+				goldTxt.setText(gold);
+				btn.passive.apply();
+				LK.getSound('buy').play();
+				rerollStore();
+			}
+			return;
+		}
+	}
+	// Drag hero
+	dragNode = hero;
+	handleMove(x, y, obj);
+};
+game.up = function (x, y, obj) {
+	dragNode = null;
+};
+// Shoot logic
+function shootAt(tx, ty) {
+	if (hero.shootCooldown > 0) return;
+	hero.shootCooldown = hero.shootInterval;
+	var dx = tx - hero.x;
+	var dy = ty - hero.y;
+	var d = Math.sqrt(dx * dx + dy * dy);
+	if (d < 0.1) {
+		dx = 0;
+		dy = -1;
+		d = 1;
+	}
+	var spread = 0;
+	var n = 1;
+	var big = false;
+	for (var i = 0; i < passives.length; ++i) {
+		if (passives[i].id === 'spread') n = 3;
+		if (passives[i].id === 'bigshot') big = true;
+	}
+	for (var i = 0; i < n; ++i) {
+		var b = new HeroBullet();
+		b.x = hero.x;
+		b.y = hero.y;
+		var angle = Math.atan2(dy, dx);
+		if (n > 1) angle += (i - 1) * 0.18;
+		b.dirX = Math.cos(angle);
+		b.dirY = Math.sin(angle);
+		if (big) {
+			b.scaleX = b.scaleY = 1.7;
+			b.radius *= 1.7;
+		}
+		heroBullets.push(b);
+		game.addChild(b);
+	}
+	LK.getSound('shoot').play();
+}
+// Touch anywhere to shoot
+game.on('down', function (x, y, obj) {
+	// Don't shoot if clicking store
+	for (var i = 0; i < storeBtns.length; ++i) {
+		var btn = storeBtns[i];
+		var bx = btn.x - 420,
+			by = btn.y,
+			bw = 420,
+			bh = 120;
+		if (x >= bx && x <= bx + bw && y >= by && y <= by + bh) return;
+	}
+	shootAt(x, y);
+});
+// Helper: collision
+function circlesIntersect(a, b) {
+	var dx = a.x - b.x,
+		dy = a.y - b.y;
+	var r = (a.radius || 40) + (b.radius || 40);
+	return dx * dx + dy * dy < r * r;
+}
+// Update GUI
+function updateHP() {
+	var s = '';
+	for (var i = 0; i < hero.hp; ++i) s += '❤';
+	hpTxt.setText(s);
+}
+// Main update
+game.update = function () {
+	// Hero update
+	hero.update();
+	// Regen passive
+	for (var i = 0; i < passives.length; ++i) {
+		if (passives[i].id === 'regen') {
+			passives[i].timer++;
+			if (passives[i].timer >= 60 * 12) {
+				hero.hp++;
+				updateHP();
+				passives[i].timer = 0;
+			}
+		}
+	}
+	// Hero bullets
+	for (var i = heroBullets.length - 1; i >= 0; --i) {
+		var b = heroBullets[i];
+		b.update();
+		// Offscreen
+		if (b.x < -60 || b.x > 2048 + 60 || b.y < -60 || b.y > 2732 + 60) {
+			b.destroy();
+			heroBullets.splice(i, 1);
+			continue;
+		}
+		// Hit monster
+		var pierced = false;
+		for (var j = monsters.length - 1; j >= 0; --j) {
+			var m = monsters[j];
+			if (m.type === 'burrower' && m.burrowed) continue;
+			if (circlesIntersect(b, m)) {
+				m.hp -= b.damage;
+				m.flash();
+				LK.getSound('hit').play();
+				if (m.hp <= 0) {
+					// Drop gold
+					var g = new Gold();
+					g.x = m.x;
+					g.y = m.y;
+					g.vx = (Math.random() - 0.5) * 8;
+					g.vy = (Math.random() - 0.5) * 8;
+					golds.push(g);
+					game.addChild(g);
+					LK.getSound('monsterdie').play();
+					m.destroy();
+					monsters.splice(j, 1);
+				}
+				// Pierce?
+				var pierce = 0;
+				for (var k = 0; k < passives.length; ++k) if (passives[k].id === 'pierce') pierce++;
+				if (pierce > 0 && !pierced) {
+					b.damage--;
+					pierced = true;
+					if (b.damage <= 0) {
+						b.destroy();
+						heroBullets.splice(i, 1);
+					}
+				} else {
+					b.destroy();
+					heroBullets.splice(i, 1);
+				}
+				break;
+			}
+		}
+	}
+	// Monster bullets
+	for (var i = monsterBullets.length - 1; i >= 0; --i) {
+		var b = monsterBullets[i];
+		b.update();
+		if (b.x < -60 || b.x > 2048 + 60 || b.y < -60 || b.y > 2732 + 60) {
+			b.destroy();
+			monsterBullets.splice(i, 1);
+			continue;
+		}
+		// Hit hero
+		if (hero.invuln === 0 && circlesIntersect(b, hero)) {
+			hero.hp--;
+			updateHP();
+			hero.invuln = 40;
+			hero.flash();
+			b.destroy();
+			monsterBullets.splice(i, 1);
+			if (hero.hp <= 0) {
+				LK.effects.flashScreen(0xff0000, 1000);
+				LK.showGameOver();
+				return;
+			}
+		}
+	}
+	// Monsters
+	for (var i = monsters.length - 1; i >= 0; --i) {
+		var m = monsters[i];
+		m.update();
+		// Hit hero
+		if (hero.invuln === 0 && circlesIntersect(m, hero)) {
+			hero.hp--;
+			updateHP();
+			hero.invuln = 40;
+			hero.flash();
+			if (hero.hp <= 0) {
+				LK.effects.flashScreen(0xff0000, 1000);
+				LK.showGameOver();
+				return;
+			}
+		}
+	}
+	// Gold
+	for (var i = golds.length - 1; i >= 0; --i) {
+		var g = golds[i];
+		g.update();
+		// Magnet passive
+		for (var j = 0; j < passives.length; ++j) {
+			if (passives[j].id === 'goldboost') {
+				var dx = hero.x - g.x,
+					dy = hero.y - g.y;
+				var d = Math.sqrt(dx * dx + dy * dy);
+				if (d < 600) {
+					g.vx += dx / d * 2.5;
+					g.vy += dy / d * 2.5;
+				}
+			}
+		}
+		// Pick up
+		if (circlesIntersect(g, hero)) {
+			gold++;
+			goldTxt.setText(gold);
+			LK.getSound('pickup').play();
+			// Lifesteal
+			for (var j = 0; j < passives.length; ++j) {
+				if (passives[j].id === 'lifesteal') {
+					passives[j].counter++;
+					if (passives[j].counter >= 8) {
+						hero.hp++;
+						updateHP();
+						passives[j].counter = 0;
+					}
+				}
+			}
+			g.destroy();
+			golds.splice(i, 1);
+		}
+	}
+	// Store button highlight
+	for (var i = 0; i < storeBtns.length; ++i) {
+		var btn = storeBtns[i];
+		var bx = btn.x - 420,
+			by = btn.y,
+			bw = 420,
+			bh = 120;
+		if (game.lastDown && game.lastDown.x >= bx && game.lastDown.x <= bx + bw && game.lastDown.y >= by && game.lastDown.y <= by + bh) {
+			if (!btn.hl) {
+				btn.hl = btn.attachAsset('storebtnhl', {
+					anchorX: 1,
+					anchorY: 0
+				});
+				btn.setChildIndex(btn.hl, 0);
+			}
+		} else {
+			if (btn.hl) {
+				btn.hl.destroy();
+				btn.hl = null;
+			}
+		}
+	}
+	// Spawn monsters
+	if (LK.ticks % 60 === 0 && monsters.length < 12) {
+		spawnMonster();
+	}
+};
+// Track last down for store highlight
+game.lastDown = null;
+game.on('down', function (x, y, obj) {
+	game.lastDown = {
+		x: x,
+		y: y
+	};
+});
+game.on('up', function (x, y, obj) {
+	game.lastDown = null;
 });
\ No newline at end of file