/**** 
* Classes
****/ 
// Bullet class
var Bullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletAsset = self.attachAsset('bullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.radius = bulletAsset.width / 2;
	self.vx = 0;
	self.vy = 0;
	self.lastX = 0;
	self.lastY = 0;
	self.update = function () {
		self.lastX = self.x;
		self.lastY = self.y;
		self.x += self.vx;
		self.y += self.vy;
		// Wall bounce
		if (self.x - self.radius <= ARENA_X && self.lastX - self.radius > ARENA_X) {
			self.x = ARENA_X + self.radius;
			self.vx *= -1;
		}
		if (self.x + self.radius >= ARENA_X + ARENA_SIZE && self.lastX + self.radius < ARENA_X + ARENA_SIZE) {
			self.x = ARENA_X + ARENA_SIZE - self.radius;
			self.vx *= -1;
		}
		if (self.y - self.radius <= ARENA_Y && self.lastY - self.radius > ARENA_Y) {
			self.y = ARENA_Y + self.radius;
			self.vy *= -1;
		}
		if (self.y + self.radius >= ARENA_Y + ARENA_SIZE && self.lastY + self.radius < ARENA_Y + ARENA_SIZE) {
			self.y = ARENA_Y + ARENA_SIZE - self.radius;
			self.vy *= -1;
		}
	};
	return self;
});
// Obstacle class
var Obstacle = Container.expand(function () {
	var self = Container.call(this);
	var obsAsset = self.attachAsset('obstacle', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.width = obsAsset.width;
	self.height = obsAsset.height;
	return self;
});
// Player class
var Player = Container.expand(function () {
	var self = Container.call(this);
	var playerAsset = self.attachAsset('player', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.radius = playerAsset.width / 2;
	return self;
});
// Target class
var Target = Container.expand(function () {
	var self = Container.call(this);
	var targetAsset = self.attachAsset('target', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.radius = targetAsset.width / 2;
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x000000
});

/**** 
* Game Code
****/ 
// Arena and gameplay variables
var ARENA_SIZE = 1800; // Square arena, fits well in 2048x2732
var ARENA_X = (2048 - ARENA_SIZE) / 2;
var ARENA_Y = (2732 - ARENA_SIZE) / 2;
var player = null;
var target = null;
var bullets = [];
var obstacles = [];
var level = 1;
var isAiming = false;
var aimLine = null;
var aimStart = null;
var aimEnd = null;
function setupLevel(lvl) {
	// Clear previous
	if (player) player.destroy();
	if (target) target.destroy();
	for (var i = 0; i < bullets.length; ++i) bullets[i].destroy();
	bullets = [];
	for (var i = 0; i < obstacles.length; ++i) obstacles[i].destroy();
	obstacles = [];
	// Player at bottom center
	player = new Player();
	player.x = ARENA_X + ARENA_SIZE / 2;
	player.y = ARENA_Y + ARENA_SIZE - 120;
	game.addChild(player);
	// Target at top center
	target = new Target();
	target.x = ARENA_X + ARENA_SIZE / 2;
	target.y = ARENA_Y + 120;
	game.addChild(target);
	// Obstacles for level > 1
	if (lvl > 1) {
		var obsCount = Math.min(lvl - 1, 5);
		for (var i = 0; i < obsCount; ++i) {
			var obs = new Obstacle();
			// Distribute obstacles at different positions, not just center
			// Alternate between left, right, and center, and randomize Y
			var posType = i % 3;
			var margin = 200;
			var xPos;
			if (posType === 0) {
				// Left third
				xPos = ARENA_X + margin + obs.width / 2;
			} else if (posType === 1) {
				// Right third
				xPos = ARENA_X + ARENA_SIZE - margin - obs.width / 2;
			} else {
				// Center
				xPos = ARENA_X + ARENA_SIZE / 2;
			}
			// Y position: spread vertically, but randomize a bit
			var yBase = ARENA_Y + ARENA_SIZE / (obsCount + 1) * (i + 1);
			var yRand = Math.random() * 120 - 60; // -60 to +60 px
			obs.x = xPos;
			obs.y = yBase + yRand;
			game.addChild(obs);
			obstacles.push(obs);
		}
	}
}
setupLevel(level);
// Aiming and shooting
game.down = function (x, y, obj) {
	// Only allow aiming if no bullet is in play
	if (bullets.length === 0) {
		isAiming = true;
		aimStart = {
			x: player.x,
			y: player.y
		};
		aimEnd = {
			x: x,
			y: y
		};
	}
};
game.move = function (x, y, obj) {
	if (isAiming) {
		aimEnd = {
			x: x,
			y: y
		};
	}
};
game.up = function (x, y, obj) {
	if (isAiming) {
		// Fire bullet
		var dx = aimEnd.x - player.x;
		var dy = aimEnd.y - player.y;
		var len = Math.sqrt(dx * dx + dy * dy);
		if (len > 10) {
			var bullet = new Bullet();
			bullet.x = player.x;
			bullet.y = player.y;
			var speed = 30;
			bullet.vx = dx / len * speed;
			bullet.vy = dy / len * speed;
			bullets.push(bullet);
			game.addChild(bullet);
		}
		isAiming = false;
		aimStart = null;
		aimEnd = null;
	}
};
// Main update loop
game.update = function () {
	// Draw aim line if aiming
	if (isAiming && aimStart && aimEnd) {
		if (!aimLine) {
			aimLine = LK.getAsset('aimLine', {
				anchorX: 0,
				anchorY: 0
			});
			game.addChild(aimLine);
		}
		// Set aimLine position and size
		var dx = aimEnd.x - aimStart.x;
		var dy = aimEnd.y - aimStart.y;
		var len = Math.sqrt(dx * dx + dy * dy);
		aimLine.x = aimStart.x;
		aimLine.y = aimStart.y;
		aimLine.width = len;
		aimLine.height = 10;
		aimLine.rotation = Math.atan2(dy, dx);
	} else if (aimLine) {
		aimLine.destroy();
		aimLine = null;
	}
	// Update bullets
	for (var i = bullets.length - 1; i >= 0; --i) {
		var b = bullets[i];
		b.update();
		// Check collision with target
		var dx = b.x - target.x;
		var dy = b.y - target.y;
		var dist = Math.sqrt(dx * dx + dy * dy);
		if (dist < b.radius + target.radius) {
			// Hit! Next level
			b.destroy();
			bullets.splice(i, 1);
			level += 1;
			setupLevel(level);
			return;
		}
		// Check collision with obstacles
		for (var j = 0; j < obstacles.length; ++j) {
			var obs = obstacles[j];
			var left = obs.x - obs.width / 2;
			var right = obs.x + obs.width / 2;
			var top = obs.y - obs.height / 2;
			var bottom = obs.y + obs.height / 2;
			// Simple AABB collision
			if (b.x + b.radius > left && b.x - b.radius < right && b.y + b.radius > top && b.y - b.radius < bottom) {
				// Reflect bullet: pick axis of minimum penetration
				var overlapX = Math.min(Math.abs(b.x + b.radius - left), Math.abs(b.x - b.radius - right));
				var overlapY = Math.min(Math.abs(b.y + b.radius - top), Math.abs(b.y - b.radius - bottom));
				if (overlapX < overlapY) {
					b.vx *= -1;
				} else {
					b.vy *= -1;
				}
			}
		}
		// Remove bullet if out of arena for too long (failsafe)
		if (b.x < ARENA_X - 200 || b.x > ARENA_X + ARENA_SIZE + 200 || b.y < ARENA_Y - 200 || b.y > ARENA_Y + ARENA_SIZE + 200) {
			b.destroy();
			bullets.splice(i, 1);
		}
	}
};

===================================================================
--- original.js
+++ change.js
@@ -115,10 +115,28 @@
 	if (lvl > 1) {
 		var obsCount = Math.min(lvl - 1, 5);
 		for (var i = 0; i < obsCount; ++i) {
 			var obs = new Obstacle();
-			obs.x = ARENA_X + ARENA_SIZE / 2;
-			obs.y = ARENA_Y + ARENA_SIZE / (obsCount + 1) * (i + 1);
+			// Distribute obstacles at different positions, not just center
+			// Alternate between left, right, and center, and randomize Y
+			var posType = i % 3;
+			var margin = 200;
+			var xPos;
+			if (posType === 0) {
+				// Left third
+				xPos = ARENA_X + margin + obs.width / 2;
+			} else if (posType === 1) {
+				// Right third
+				xPos = ARENA_X + ARENA_SIZE - margin - obs.width / 2;
+			} else {
+				// Center
+				xPos = ARENA_X + ARENA_SIZE / 2;
+			}
+			// Y position: spread vertically, but randomize a bit
+			var yBase = ARENA_Y + ARENA_SIZE / (obsCount + 1) * (i + 1);
+			var yRand = Math.random() * 120 - 60; // -60 to +60 px
+			obs.x = xPos;
+			obs.y = yBase + yRand;
 			game.addChild(obs);
 			obstacles.push(obs);
 		}
 	}