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

/**** 
* Classes
****/ 
// Bullet
var Bullet = Container.expand(function () {
	var self = Container.call(this);
	var bullet = self.attachAsset('bullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.width = bullet.width;
	self.height = bullet.height;
	self.speed = -36; // Upwards
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
// Enemy base class
var Enemy = Container.expand(function () {
	var self = Container.call(this);
	self.type = 'enemy';
	self.hp = 1;
	self.speed = 8;
	self.scoreValue = 1;
	self.update = function () {};
	return self;
});
// Skeleton enemy
var Skeleton = Enemy.expand(function () {
	var self = Enemy.call(this);
	var skeleton = self.attachAsset('enemy_skeleton', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.width = skeleton.width;
	self.height = skeleton.height;
	self.hp = 1;
	self.speed = 12 + Math.random() * 4;
	self.scoreValue = 2;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
// Goblin enemy
var Goblin = Enemy.expand(function () {
	var self = Enemy.call(this);
	var goblin = self.attachAsset('enemy_goblin', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.width = goblin.width;
	self.height = goblin.height;
	self.hp = 2;
	self.speed = 10 + Math.random() * 4;
	self.scoreValue = 3;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
// Bat enemy
var Bat = Enemy.expand(function () {
	var self = Enemy.call(this);
	var bat = self.attachAsset('enemy_bat', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.width = bat.width;
	self.height = bat.height;
	self.hp = 1;
	self.speed = 18 + Math.random() * 6;
	self.scoreValue = 2;
	self.update = function () {
		self.y += self.speed;
		self.x += Math.sin(LK.ticks / 12 + self._batWobble) * 8;
	};
	self._batWobble = Math.random() * Math.PI * 2;
	return self;
});
// Player Minecart
var Minecart = Container.expand(function () {
	var self = Container.call(this);
	var cart = self.attachAsset('minecart', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.width = cart.width;
	self.height = cart.height;
	self.weapon = 'gun'; // 'gun' or 'knife'
	self.weaponLevel = 1; // Upgrades increase this
	self.invincible = false;
	self.invincibleTimer = 0;
	self.attackCooldown = 0;
	self.knifeSwinging = false;
	self.knife = null;
	// Flash minecart when hit
	self.flash = function () {
		self.invincible = true;
		self.invincibleTimer = 60; // 1 second at 60fps
		tween(self, {
			alpha: 0.5
		}, {
			duration: 100,
			easing: tween.easeOut,
			onFinish: function onFinish() {
				tween(self, {
					alpha: 1
				}, {
					duration: 100
				});
			}
		});
	};
	// Switch weapon
	self.setWeapon = function (type) {
		self.weapon = type;
	};
	// Upgrade weapon
	self.upgradeWeapon = function () {
		self.weaponLevel += 1;
		if (self.weaponLevel > 3) self.weaponLevel = 3;
	};
	// Knife attack animation
	self.swingKnife = function () {
		if (self.knifeSwinging) return;
		self.knifeSwinging = true;
		if (!self.knife) {
			self.knife = self.attachAsset('knife', {
				anchorX: 0.1,
				anchorY: 0.5,
				x: self.width / 2 + 20,
				y: 0,
				rotation: 0
			});
		}
		self.knife.visible = true;
		self.knife.rotation = -0.7;
		tween(self.knife, {
			rotation: 0.7
		}, {
			duration: 180,
			easing: tween.cubicOut,
			onFinish: function onFinish() {
				self.knife.visible = false;
				self.knifeSwinging = false;
				self.knife.rotation = -0.7;
			}
		});
	};
	return self;
});
// Obstacle (rock)
var Obstacle = Container.expand(function () {
	var self = Container.call(this);
	var rock = self.attachAsset('obstacle_rock', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.width = rock.width;
	self.height = rock.height;
	self.speed = 14 + Math.random() * 6;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
// Upgrade (gun or knife)
var Upgrade = Container.expand(function () {
	var self = Container.call(this);
	self.kind = Math.random() < 0.5 ? 'gun' : 'knife';
	var assetId = self.kind === 'gun' ? 'upgrade_gun' : 'upgrade_knife';
	var upg = self.attachAsset(assetId, {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.width = upg.width;
	self.height = upg.height;
	self.speed = 10 + Math.random() * 4;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});

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

/**** 
* Game Code
****/ 
// Upgrade: Knife
// Upgrade: Gun
// Obstacle: Rock
// Enemy: Skeleton
// Enemy: Goblin
// Enemy: Bat
// Player's bullet
// Player's knife
// Minecart (player)
// Game constants
var GAME_W = 2048;
var GAME_H = 2732;
var TRACK_LEFT = 300;
var TRACK_RIGHT = GAME_W - 300;
var PLAYER_Y = GAME_H - 350;
// Game state
var minecart = null;
var bullets = [];
var enemies = [];
var obstacles = [];
var upgrades = [];
var dragNode = null;
var lastTouchX = 0;
var lastTouchY = 0;
var scoreTxt = null;
var lastScore = 0;
var gameOver = false;
var spawnTimer = 0;
var obstacleTimer = 0;
var upgradeTimer = 0;
var difficulty = 1;
var knifeHitEnemies = [];
var lastKnifeSwingTick = -100;
// Score display
scoreTxt = new Text2('0', {
	size: 120,
	fill: "#fff"
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Create player
minecart = new Minecart();
game.addChild(minecart);
minecart.x = GAME_W / 2;
minecart.y = PLAYER_Y;
// Maze navigation: drag minecart in both X and Y within maze bounds
game.down = function (x, y, obj) {
	if (gameOver) return;
	dragNode = minecart;
	lastTouchX = x;
	lastTouchY = y;
};
game.up = function (x, y, obj) {
	dragNode = null;
};
game.move = function (x, y, obj) {
	if (gameOver) return;
	if (dragNode === minecart) {
		// Allow movement in both X and Y, but clamp to maze area
		var nx = x;
		var ny = y;
		// Clamp to maze bounds (leave 100px margin on all sides)
		if (nx < 100) nx = 100;
		if (nx > GAME_W - 100) nx = GAME_W - 100;
		if (ny < 200) ny = 200;
		if (ny > GAME_H - 100) ny = GAME_H - 100;
		minecart.x = nx;
		minecart.y = ny;
	}
};
// Tap to attack (shoot or knife)
game.tap = function (x, y, obj) {
	if (gameOver) return;
	if (minecart.weapon === 'gun') {
		if (minecart.attackCooldown <= 0) {
			fireBullet();
			minecart.attackCooldown = 12 - minecart.weaponLevel * 2; // Faster with upgrades
			if (minecart.attackCooldown < 4) minecart.attackCooldown = 4;
		}
	} else if (minecart.weapon === 'knife') {
		if (LK.ticks - lastKnifeSwingTick > 18) {
			minecart.swingKnife();
			lastKnifeSwingTick = LK.ticks;
		}
	}
};
// Fire bullet(s)
function fireBullet() {
	var spread = minecart.weaponLevel;
	for (var i = 0; i < spread; ++i) {
		var b = new Bullet();
		b.x = minecart.x + (i - (spread - 1) / 2) * 40;
		b.y = minecart.y - minecart.height / 2 - 10;
		bullets.push(b);
		game.addChild(b);
	}
}
// Main update loop
game.update = function () {
	if (gameOver) return;
	// Difficulty scaling
	if (LK.ticks % 300 === 0 && difficulty < 10) {
		difficulty += 1;
	}
	// Attack cooldown
	if (minecart.attackCooldown > 0) minecart.attackCooldown -= 1;
	// Invincibility timer
	if (minecart.invincible) {
		minecart.invincibleTimer -= 1;
		if (minecart.invincibleTimer <= 0) {
			minecart.invincible = false;
		}
	}
	// Bullets update
	for (var i = bullets.length - 1; i >= 0; --i) {
		var b = bullets[i];
		b.update();
		if (b.y < -50) {
			b.destroy();
			bullets.splice(i, 1);
			continue;
		}
		// Bullet hits enemy
		for (var j = enemies.length - 1; j >= 0; --j) {
			var e = enemies[j];
			if (b.intersects(e)) {
				e.hp -= 1;
				b.destroy();
				bullets.splice(i, 1);
				if (e.hp <= 0) {
					addScore(e.scoreValue);
					e.destroy();
					enemies.splice(j, 1);
				}
				break;
			}
		}
	}
	// Enemies update (maze: hidden until close, then run at player)
	for (var i = enemies.length - 1; i >= 0; --i) {
		var e = enemies[i];
		// Track if enemy is revealed
		if (typeof e.revealed === "undefined") {
			e.revealed = false;
			e.visible = false;
			e.chasing = false;
		}
		// Reveal enemy if close to player (distance < 350px)
		var dx = e.x - minecart.x;
		var dy = e.y - minecart.y;
		var dist = Math.sqrt(dx * dx + dy * dy);
		if (!e.revealed && dist < 350) {
			e.revealed = true;
			e.visible = true;
			e.chasing = true;
		}
		// If revealed and chasing, move toward player
		if (e.revealed && e.chasing) {
			var angle = Math.atan2(minecart.y - e.y, minecart.x - e.x);
			var speed = e.speed || 10;
			e.x += Math.cos(angle) * speed;
			e.y += Math.sin(angle) * speed;
		} else if (!e.revealed) {
			// If not revealed, don't move
		}
		// Remove if out of bounds
		if (e.x < -200 || e.x > GAME_W + 200 || e.y < -200 || e.y > GAME_H + 200) {
			e.destroy();
			enemies.splice(i, 1);
			continue;
		}
		// Enemy hits minecart
		if (!minecart.invincible && e.revealed && e.intersects(minecart)) {
			minecart.flash();
			LK.effects.flashScreen(0xff0000, 600);
			// End game
			LK.showGameOver();
			gameOver = true;
			return;
		}
		// Enemy hit by knife
		if (minecart.weapon === 'knife' && minecart.knife && minecart.knife.visible && !knifeHitEnemies.includes(e)) {
			// Knife is in swing, check collision
			var knifeGlobal = minecart.toGlobal(minecart.knife.position);
			var knifeRect = new Rectangle(knifeGlobal.x - 30, knifeGlobal.y - 12, 60, 24);
			var enemyRect = new Rectangle(e.x - e.width / 2, e.y - e.height / 2, e.width, e.height);
			if (rectsIntersect(knifeRect, enemyRect)) {
				e.hp -= 1;
				knifeHitEnemies.push(e);
				if (e.hp <= 0) {
					addScore(e.scoreValue);
					e.destroy();
					enemies.splice(i, 1);
				}
			}
		}
	}
	// Reset knife hit list if knife not swinging
	if (!(minecart.knife && minecart.knife.visible)) {
		knifeHitEnemies = [];
	}
	// Obstacles update
	for (var i = obstacles.length - 1; i >= 0; --i) {
		var o = obstacles[i];
		o.update();
		if (o.y > GAME_H + 100) {
			o.destroy();
			obstacles.splice(i, 1);
			continue;
		}
		// Obstacle hits minecart
		if (!minecart.invincible && o.intersects(minecart)) {
			minecart.flash();
			LK.effects.flashScreen(0xff0000, 600);
			LK.showGameOver();
			gameOver = true;
			return;
		}
	}
	// Upgrades update
	for (var i = upgrades.length - 1; i >= 0; --i) {
		var u = upgrades[i];
		u.update();
		if (u.y > GAME_H + 100) {
			u.destroy();
			upgrades.splice(i, 1);
			continue;
		}
		// Pickup
		if (u.intersects(minecart)) {
			if (u.kind === 'gun') {
				minecart.setWeapon('gun');
				minecart.upgradeWeapon();
			} else {
				minecart.setWeapon('knife');
				minecart.upgradeWeapon();
			}
			u.destroy();
			upgrades.splice(i, 1);
		}
	}
	// Spawning enemies
	spawnTimer -= 1;
	if (spawnTimer <= 0) {
		spawnEnemy();
		spawnTimer = Math.max(24, 60 - difficulty * 4 - Math.floor(Math.random() * 10));
	}
	// Spawning obstacles
	obstacleTimer -= 1;
	if (obstacleTimer <= 0) {
		if (Math.random() < 0.5 + difficulty * 0.04) {
			spawnObstacle();
		}
		obstacleTimer = 90 + Math.floor(Math.random() * 60) - difficulty * 4;
		if (obstacleTimer < 30) obstacleTimer = 30;
	}
	// Spawning upgrades
	upgradeTimer -= 1;
	if (upgradeTimer <= 0) {
		if (Math.random() < 0.18) {
			spawnUpgrade();
		}
		upgradeTimer = 600 + Math.floor(Math.random() * 300);
	}
	// Update score display
	if (LK.getScore() !== lastScore) {
		scoreTxt.setText(LK.getScore());
		lastScore = LK.getScore();
	}
};
// Spawn enemy at random maze edge (not visible until close)
function spawnEnemy() {
	var enemyType = Math.random();
	var e = null;
	if (enemyType < 0.33) {
		e = new Bat();
	} else if (enemyType < 0.66) {
		e = new Goblin();
	} else {
		e = new Skeleton();
	}
	// Spawn at random edge of maze
	var edge = Math.floor(Math.random() * 4);
	var margin = 120;
	if (edge === 0) {
		// left
		e.x = margin;
		e.y = margin + Math.random() * (GAME_H - 2 * margin);
	} else if (edge === 1) {
		// right
		e.x = GAME_W - margin;
		e.y = margin + Math.random() * (GAME_H - 2 * margin);
	} else if (edge === 2) {
		// top
		e.x = margin + Math.random() * (GAME_W - 2 * margin);
		e.y = margin;
	} else {
		// bottom
		e.x = margin + Math.random() * (GAME_W - 2 * margin);
		e.y = GAME_H - margin;
	}
	enemies.push(e);
	game.addChild(e);
}
// Spawn obstacle
function spawnObstacle() {
	var o = new Obstacle();
	o.x = TRACK_LEFT + 80 + Math.random() * (TRACK_RIGHT - TRACK_LEFT - 160);
	o.y = -60;
	obstacles.push(o);
	game.addChild(o);
}
// Spawn upgrade
function spawnUpgrade() {
	var u = new Upgrade();
	u.x = TRACK_LEFT + 80 + Math.random() * (TRACK_RIGHT - TRACK_LEFT - 160);
	u.y = -60;
	upgrades.push(u);
	game.addChild(u);
}
// Add score
function addScore(val) {
	LK.setScore(LK.getScore() + val);
}
// Rectangle intersection helper
function rectsIntersect(r1, r2) {
	return !(r2.x > r1.x + r1.width || r2.x + r2.width < r1.x || r2.y > r1.y + r1.height || r2.y + r2.height < r1.y);
}
// Touch to attack (simulate tap on mobile)
game.down = function (origDown) {
	return function (x, y, obj) {
		if (origDown) origDown(x, y, obj);
		game.tap(x, y, obj);
	};
}(game.down);
// Reset game state on game over
LK.on('gameover', function () {
	gameOver = true;
});
// Reset game state on new game
LK.on('newgame', function () {
	gameOver = false;
	LK.setScore(0);
	scoreTxt.setText('0');
	// Remove all objects
	for (var i = 0; i < bullets.length; ++i) bullets[i].destroy();
	for (var i = 0; i < enemies.length; ++i) enemies[i].destroy();
	for (var i = 0; i < obstacles.length; ++i) obstacles[i].destroy();
	for (var i = 0; i < upgrades.length; ++i) upgrades[i].destroy();
	bullets = [];
	enemies = [];
	obstacles = [];
	upgrades = [];
	minecart.x = GAME_W / 2;
	minecart.y = PLAYER_Y;
	minecart.weapon = 'gun';
	minecart.weaponLevel = 1;
	minecart.invincible = false;
	minecart.invincibleTimer = 0;
	minecart.attackCooldown = 0;
	minecart.knifeSwinging = false;
	minecart.setWeapon('gun');
	difficulty = 1;
	spawnTimer = 0;
	obstacleTimer = 0;
	upgradeTimer = 0;
	knifeHitEnemies = [];
	lastKnifeSwingTick = -100;
});
// Initial state
spawnTimer = 0;
obstacleTimer = 60;
upgradeTimer = 600;
difficulty = 1;
gameOver = false;
LK.setScore(0);
scoreTxt.setText('0');

===================================================================
--- original.js
+++ change.js