/**** 
* Plugins
****/ 
var tween = LK.import("@upit/tween.v1");
var storage = LK.import("@upit/storage.v1", {
	highScore: 0,
	lastScore: 0
});

/**** 
* Classes
****/ 
var Bullet = Container.expand(function () {
	var self = Container.call(this);
	self.bulletGraphics = self.attachAsset('bullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 20;
	self.damage = 1;
	self.isPlayerBullet = true;
	self.update = function () {
		self.x += self.speed;
		// Auto destroy when off screen
		if (self.x > 2148) {
			self.destroy();
		}
	};
	return self;
});
var Enemy = Container.expand(function () {
	var self = Container.call(this);
	self.enemyGraphics = self.attachAsset('enemy', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speedX = -5;
	self.speedY = 0;
	self.health = 5;
	self.score = 100;
	self.canShoot = false;
	self.shootTimer = 0;
	self.shootInterval = 120; // 2 seconds at 60fps
	self.update = function () {
		self.x += self.speedX;
		self.y += self.speedY;
		// Simple movement pattern
		if (self.movePattern === 'sine') {
			self.y += Math.sin(LK.ticks * 0.05) * 2;
		} else if (self.movePattern === 'zigzag') {
			if (LK.ticks % 60 === 0) {
				self.speedY = -self.speedY || (Math.random() > 0.5 ? 3 : -3);
			}
		}
		// Shooting logic
		if (self.canShoot) {
			self.shootTimer++;
			if (self.shootTimer >= self.shootInterval) {
				self.shootTimer = 0;
				self.shoot();
			}
		}
		// Auto destroy when off screen
		if (self.x < -100) {
			self.destroy();
		}
	};
	self.shoot = function () {
		if (!game) {
			return;
		}
		var bullet = new Bullet();
		bullet.x = self.x - 20;
		bullet.y = self.y;
		bullet.speed = -15;
		bullet.isPlayerBullet = false;
		bullet.bulletGraphics.tint = 0xff0000; // Red enemy bullets
		game.addChild(bullet);
		game.enemyBullets.push(bullet);
	};
	self.takeDamage = function (damage) {
		self.health -= damage;
		// Flash red when taking damage
		LK.effects.flashObject(self, 0xff0000, 200);
		if (self.health <= 0) {
			// Explosion effect
			LK.getSound('explosion').play();
			LK.effects.flashObject(self, 0xffffff, 300);
			// Add score
			game.increaseScore(self.score);
			// Potentially drop powerup (20% chance)
			if (Math.random() < 0.2) {
				game.spawnPowerup(self.x, self.y);
			}
			self.destroy();
		}
	};
	return self;
});
var Boss = Enemy.expand(function () {
	var self = Enemy.call(this);
	// Replace graphics with boss graphic
	self.enemyGraphics.destroy();
	self.enemyGraphics = self.attachAsset('boss', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.health = 75;
	self.score = 2000;
	self.speedX = -2;
	self.canShoot = true;
	self.shootInterval = 60; // 1 second at 60fps
	self.phase = 1;
	self.phaseTimer = 0;
	self.isBoss = true;
	// Override update function
	self.update = function () {
		self.phaseTimer++;
		// Boss movement based on phases
		if (self.phase === 1) {
			// Enter the screen
			if (self.x > 1600) {
				self.x += self.speedX;
			} else {
				self.phase = 2;
				self.phaseTimer = 0;
			}
		} else if (self.phase === 2) {
			// Move up and down
			self.y += Math.sin(self.phaseTimer * 0.03) * 4;
			// Shooting pattern
			if (self.phaseTimer % 20 === 0) {
				self.shoot();
			}
			// Phase transition
			if (self.phaseTimer > 300) {
				self.phase = 3;
				self.phaseTimer = 0;
			}
		} else if (self.phase === 3) {
			// Charge at player
			if (self.phaseTimer < 60) {
				// Prepare
				self.speedX = 0;
			} else if (self.phaseTimer < 120) {
				// Charge
				self.x -= 15;
			} else {
				// Return to position
				if (self.x < 1600) {
					self.x += 5;
				} else {
					self.phase = 2;
					self.phaseTimer = 0;
				}
			}
		}
		// Health-based phase changes
		if (self.health < 25 && self.shootInterval > 40) {
			self.shootInterval = 40; // Shoot faster when at low health
		}
	};
	// Override shoot function for more complex patterns
	self.shoot = function () {
		if (!game) {
			return;
		}
		// Different shooting patterns based on phase
		if (self.phase === 2) {
			// Spread shot
			for (var i = -2; i <= 2; i++) {
				var bullet = new Bullet();
				bullet.x = self.x - 50;
				bullet.y = self.y;
				bullet.speed = -15;
				bullet.speedY = i * 2;
				bullet.isPlayerBullet = false;
				bullet.bulletGraphics.tint = 0xff0000;
				// Custom update for diagonal movement
				var originalUpdate = bullet.update;
				bullet.update = function () {
					this.x += this.speed;
					this.y += this.speedY;
					// Off screen check
					if (this.x < -100 || this.y < -100 || this.y > 2832) {
						this.destroy();
					}
				};
				game.addChild(bullet);
				game.enemyBullets.push(bullet);
			}
		} else if (self.phase === 3) {
			// Aimed shot at player
			var bullet = new Bullet();
			bullet.x = self.x - 50;
			bullet.y = self.y;
			// Calculate angle to player
			var dx = game.player.x - bullet.x;
			var dy = game.player.y - bullet.y;
			var angle = Math.atan2(dy, dx);
			bullet.speed = -15 * Math.cos(angle);
			bullet.speedY = 15 * Math.sin(angle);
			bullet.isPlayerBullet = false;
			bullet.bulletGraphics.tint = 0xff5500; // Orange for aimed shots
			// Custom update for angle-based movement
			bullet.update = function () {
				this.x += this.speed;
				this.y += this.speedY;
				// Off screen check
				if (this.x < -100 || this.y < -100 || this.y > 2832) {
					this.destroy();
				}
			};
			game.addChild(bullet);
			game.enemyBullets.push(bullet);
		}
		LK.getSound('shoot').play();
	};
	return self;
});
var Obstacle = Container.expand(function () {
	var self = Container.call(this);
	self.obstacleGraphics = self.attachAsset('obstacle', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = -8;
	self.update = function () {
		self.x += self.speed;
		// Auto destroy when off screen
		if (self.x < -100) {
			self.destroy();
		}
	};
	return self;
});
var Player = Container.expand(function () {
	var self = Container.call(this);
	self.playerGraphics = self.attachAsset('player', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.health = 5;
	self.maxHealth = 5;
	self.shield = 0;
	self.weaponLevel = 1;
	self.specialMeter = 0;
	self.specialMax = 100;
	self.shootCooldown = 0;
	self.invulnerable = 0;
	self.update = function () {
		// Shooting cooldown
		if (self.shootCooldown > 0) {
			self.shootCooldown--;
		}
		// Invulnerability frames
		if (self.invulnerable > 0) {
			self.invulnerable--;
			// Flash effect during invulnerability
			if (LK.ticks % 5 === 0) {
				self.playerGraphics.alpha = self.playerGraphics.alpha === 1 ? 0.5 : 1;
			}
		} else {
			self.playerGraphics.alpha = 1;
		}
		// Gentle hover effect
		self.y += Math.sin(LK.ticks * 0.05) * 0.5;
	};
	self.shoot = function () {
		if (self.shootCooldown > 0) {
			return;
		}
		LK.getSound('shoot').play();
		// Different shooting patterns based on weapon level
		if (self.weaponLevel === 1) {
			// Single shot
			var bullet = new Bullet();
			bullet.x = self.x + 50;
			bullet.y = self.y;
			game.addChild(bullet);
			game.playerBullets.push(bullet);
			self.shootCooldown = 10;
		} else if (self.weaponLevel === 2) {
			// Double shot
			for (var i = -1; i <= 1; i += 2) {
				var bullet = new Bullet();
				bullet.x = self.x + 50;
				bullet.y = self.y + i * 20;
				game.addChild(bullet);
				game.playerBullets.push(bullet);
			}
			self.shootCooldown = 8;
		} else if (self.weaponLevel >= 3) {
			// Triple shot
			var center = new Bullet();
			center.x = self.x + 60;
			center.y = self.y;
			game.addChild(center);
			game.playerBullets.push(center);
			for (var i = -1; i <= 1; i += 2) {
				var side = new Bullet();
				side.x = self.x + 40;
				side.y = self.y + i * 30;
				game.addChild(side);
				game.playerBullets.push(side);
			}
			self.shootCooldown = 6;
		}
		// Increase special meter slightly with each shot
		self.specialMeter = Math.min(self.specialMeter + 1, self.specialMax);
		game.updateSpecialMeter();
	};
	self.activateSpecial = function () {
		if (self.specialMeter < self.specialMax) {
			return;
		}
		LK.getSound('special').play();
		// Create special attack
		var special = new SpecialAttack();
		special.x = self.x;
		special.y = self.y;
		game.addChild(special);
		game.specialAttacks.push(special);
		// Make player briefly invulnerable
		self.invulnerable = 60;
		// Reset special meter
		self.specialMeter = 0;
		game.updateSpecialMeter();
	};
	self.takeDamage = function () {
		if (self.invulnerable > 0) {
			return;
		}
		// Shield absorbs damage first
		if (self.shield > 0) {
			self.shield--;
			LK.getSound('damage').play();
			LK.effects.flashObject(self, 0x3498db, 300); // Blue flash for shield hit
		} else {
			self.health--;
			LK.getSound('damage').play();
			LK.effects.flashObject(self, 0xff0000, 300); // Red flash for health hit
			// Set invulnerability frames
			self.invulnerable = 60;
			// Game over check
			if (self.health <= 0) {
				// Store score
				storage.lastScore = game.score;
				if (game.score > storage.highScore) {
					storage.highScore = game.score;
				}
				LK.showGameOver();
			}
		}
		game.updateHealthDisplay();
	};
	self.collectPowerup = function (powerup) {
		LK.getSound('powerup').play();
		if (powerup.type === 'health') {
			self.health = Math.min(self.health + 1, self.maxHealth);
		} else if (powerup.type === 'shield') {
			self.shield = Math.min(self.shield + 2, 3); // Max 3 shield points
		} else if (powerup.type === 'weapon') {
			self.weaponLevel = Math.min(self.weaponLevel + 1, 3);
		} else if (powerup.type === 'special') {
			self.specialMeter = self.specialMax; // Fill special meter
		}
		game.updateHealthDisplay();
		game.updateSpecialMeter();
		// Visual effect
		LK.effects.flashObject(self, 0xffffff, 300);
	};
	// Touch/mouse controls
	self.down = function (x, y, obj) {
		game.isDragging = true;
	};
	return self;
});
var PowerUp = Container.expand(function () {
	var self = Container.call(this);
	self.powerupGraphics = self.attachAsset('powerup', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = -3;
	self.type = 'health'; // Default power-up type
	// Set color based on type
	if (self.type === 'health') {
		self.powerupGraphics.tint = 0x2ecc71; // Green
	} else if (self.type === 'shield') {
		self.powerupGraphics.tint = 0x3498db; // Blue
	} else if (self.type === 'weapon') {
		self.powerupGraphics.tint = 0xf1c40f; // Yellow
	} else if (self.type === 'special') {
		self.powerupGraphics.tint = 0x9b59b6; // Purple
	}
	self.update = function () {
		self.x += self.speed;
		// Gentle floating effect
		self.y += Math.sin(LK.ticks * 0.1) * 0.5;
		// Auto destroy when off screen
		if (self.x < -100) {
			self.destroy();
		}
	};
	return self;
});
var SpecialAttack = Container.expand(function () {
	var self = Container.call(this);
	self.attackGraphics = self.attachAsset('specialAttack', {
		anchorX: 0.5,
		anchorY: 0.5,
		alpha: 0.7
	});
	self.duration = 60; // 1 second at 60fps
	self.counter = 0;
	self.damage = 5;
	self.update = function () {
		self.counter++;
		self.x += 10;
		// Flash effect
		if (self.counter % 5 === 0) {
			self.attackGraphics.alpha = self.attackGraphics.alpha === 0.7 ? 0.9 : 0.7;
		}
		// Auto destroy when duration ends
		if (self.counter >= self.duration) {
			self.destroy();
		}
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x0e0e2a
});

/**** 
* Game Code
****/ 
// Game variables
game.score = 0;
game.level = 1;
game.waveTimer = 0;
game.bossActive = false;
game.spawnRate = 120; // Enemy spawn rate (frames)
game.isDragging = false;
game.autoShoot = true;
game.autoShootTimer = 0;
// Array containers for game objects
game.playerBullets = [];
game.enemyBullets = [];
game.enemies = [];
game.powerups = [];
game.obstacles = [];
game.specialAttacks = [];
// Create background
var background = game.addChild(LK.getAsset('background', {
	anchorX: 0.5,
	anchorY: 0.5,
	x: 1024,
	y: 1366
}));
// Create player
game.player = new Player();
game.player.x = 300;
game.player.y = 1366; // Center vertically
game.addChild(game.player);
// Create UI
// Score display
var scoreTxt = new Text2('SCORE: 0', {
	size: 80,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Create touch screen buttons for movement
var leftBtn = game.addChild(LK.getAsset('powerup', {
	anchorX: 0.5,
	anchorY: 0.5,
	x: 100,
	y: 2500,
	scaleX: 2,
	scaleY: 2,
	tint: 0x3498db
}));
var rightBtn = game.addChild(LK.getAsset('powerup', {
	anchorX: 0.5,
	anchorY: 0.5,
	x: 400,
	y: 2500,
	scaleX: 2,
	scaleY: 2,
	tint: 0x3498db
}));
var upBtn = game.addChild(LK.getAsset('powerup', {
	anchorX: 0.5,
	anchorY: 0.5,
	x: 250,
	y: 2400,
	scaleX: 2,
	scaleY: 2,
	tint: 0x3498db
}));
var downBtn = game.addChild(LK.getAsset('powerup', {
	anchorX: 0.5,
	anchorY: 0.5,
	x: 250,
	y: 2600,
	scaleX: 2,
	scaleY: 2,
	tint: 0x3498db
}));
// Button event handlers
leftBtn.down = function () {
	game.player.x = Math.max(85, game.player.x - 10);
};
rightBtn.down = function () {
	game.player.x = Math.min(1963, game.player.x + 10);
};
upBtn.down = function () {
	game.player.y = Math.max(85, game.player.y - 10);
};
downBtn.down = function () {
	game.player.y = Math.min(2647, game.player.y + 10);
};
// Health display
var healthTxt = new Text2('HEALTH: 5', {
	size: 60,
	fill: 0x2ECC71
});
healthTxt.anchor.set(0, 0);
healthTxt.x = 120;
healthTxt.y = 100;
LK.gui.addChild(healthTxt);
// Shield display
var shieldTxt = new Text2('SHIELD: 0', {
	size: 60,
	fill: 0x3498DB
});
shieldTxt.anchor.set(0, 0);
shieldTxt.x = 120;
shieldTxt.y = 170;
LK.gui.addChild(shieldTxt);
// Special meter
var specialTxt = new Text2('SPECIAL: 0%', {
	size: 60,
	fill: 0x9B59B6
});
specialTxt.anchor.set(0, 0);
specialTxt.x = 120;
specialTxt.y = 240;
LK.gui.addChild(specialTxt);
// Level display
var levelTxt = new Text2('LEVEL 1', {
	size: 60,
	fill: 0xF1C40F
});
levelTxt.anchor.set(1, 0);
levelTxt.x = -120;
levelTxt.y = 100;
LK.gui.right.addChild(levelTxt);
// Special attack button
var specialBtn = game.addChild(LK.getAsset('powerup', {
	anchorX: 0.5,
	anchorY: 0.5,
	x: 1900,
	y: 2500,
	scaleX: 2,
	scaleY: 2,
	tint: 0x9b59b6
}));
// Update UI functions
game.updateScoreDisplay = function () {
	scoreTxt.setText('SCORE: ' + game.score);
};
game.updateHealthDisplay = function () {
	healthTxt.setText('HEALTH: ' + game.player.health);
	shieldTxt.setText('SHIELD: ' + game.player.shield);
};
game.updateSpecialMeter = function () {
	var percentage = Math.floor(game.player.specialMeter / game.player.specialMax * 100);
	specialTxt.setText('SPECIAL: ' + percentage + '%');
	// Visual indication of special readiness
	if (percentage >= 100) {
		specialTxt.setStyle({
			fill: 0xFFFFFF
		});
		tween(specialTxt, {
			alpha: 0.5
		}, {
			duration: 500,
			easing: tween.easeInOut,
			onFinish: function onFinish() {
				tween(specialTxt, {
					alpha: 1
				}, {
					duration: 500,
					easing: tween.easeInOut
				});
			}
		});
	} else {
		specialTxt.setStyle({
			fill: 0x9B59B6
		});
		specialTxt.alpha = 1;
	}
};
game.updateLevelDisplay = function () {
	levelTxt.setText('LEVEL ' + game.level);
};
// Spawn functions
game.spawnEnemy = function (type) {
	var enemy = new Enemy();
	enemy.x = 2148; // Just off-screen to the right
	enemy.y = 500 + Math.random() * 1400; // Random y position
	// Configure enemy type
	if (type === 'basic') {
		enemy.movePattern = 'none';
		enemy.canShoot = false;
	} else if (type === 'shooter') {
		enemy.movePattern = 'none';
		enemy.canShoot = true;
		enemy.enemyGraphics.tint = 0xe67e22; // Orange
	} else if (type === 'fast') {
		enemy.movePattern = 'zigzag';
		enemy.speedX = -10;
		enemy.health = 2;
		enemy.enemyGraphics.tint = 0xe74c3c; // Red
	} else if (type === 'tank') {
		enemy.movePattern = 'sine';
		enemy.speedX = -3;
		enemy.health = 12;
		enemy.score = 250;
		enemy.enemyGraphics.scaleX = 1.5;
		enemy.enemyGraphics.scaleY = 1.5;
		enemy.enemyGraphics.tint = 0x7f8c8d; // Gray
	}
	game.addChild(enemy);
	game.enemies.push(enemy);
	return enemy;
};
game.spawnBoss = function () {
	// Only one boss at a time
	if (game.bossActive) {
		return;
	}
	game.bossActive = true;
	var boss = new Boss();
	boss.x = 2300; // Start off-screen
	boss.y = 1366; // Center vertically
	game.addChild(boss);
	game.enemies.push(boss);
	return boss;
};
game.spawnObstacle = function () {
	var obstacle = new Obstacle();
	obstacle.x = 2148; // Just off-screen to the right
	obstacle.y = 400 + Math.random() * 1600; // Random y position
	game.addChild(obstacle);
	game.obstacles.push(obstacle);
	return obstacle;
};
game.spawnPowerup = function (x, y) {
	var powerup = new PowerUp();
	powerup.x = x;
	powerup.y = y;
	// Random powerup type
	var types = ['health', 'shield', 'weapon', 'special'];
	var weights = [0.3, 0.3, 0.2, 0.2]; // Higher chance for health/shield
	var total = 0;
	var random = Math.random();
	for (var i = 0; i < types.length; i++) {
		total += weights[i];
		if (random <= total) {
			powerup.type = types[i];
			break;
		}
	}
	// Set color based on type
	if (powerup.type === 'health') {
		powerup.powerupGraphics.tint = 0x2ecc71; // Green
	} else if (powerup.type === 'shield') {
		powerup.powerupGraphics.tint = 0x3498db; // Blue
	} else if (powerup.type === 'weapon') {
		powerup.powerupGraphics.tint = 0xf1c40f; // Yellow
	} else if (powerup.type === 'special') {
		powerup.powerupGraphics.tint = 0x9b59b6; // Purple
	}
	game.addChild(powerup);
	game.powerups.push(powerup);
	return powerup;
};
// Score function
game.increaseScore = function (amount) {
	game.score += amount;
	game.updateScoreDisplay();
	// Level up every 5000 points
	if (game.score > 0 && game.score % 5000 === 0) {
		game.levelUp();
	}
};
game.levelUp = function () {
	game.level++;
	game.updateLevelDisplay();
	// Spawn boss every 3 levels
	if (game.level % 3 === 0) {
		game.spawnBoss();
	}
	// Increase difficulty
	game.spawnRate = Math.max(60, game.spawnRate - 10);
	// Flash screen
	LK.effects.flashScreen(0xf1c40f, 500); // Yellow flash
};
// Event handlers
game.down = function (x, y, obj) {
	// Special button handling
	if (obj === specialBtn && game.player.specialMeter >= game.player.specialMax) {
		game.player.activateSpecial();
		return;
	}
	// Player shooting
	game.player.shoot();
	// Start dragging
	game.isDragging = true;
};
game.up = function (x, y, obj) {
	game.isDragging = false;
};
game.move = function (x, y, obj) {
	if (game.isDragging) {
		// Calculate movement based on touchpad input
		var deltaX = x - game.player.x;
		var deltaY = y - game.player.y;
		// Apply movement with a sensitivity factor
		game.player.x += deltaX * 0.1;
		game.player.y += deltaY * 0.1;
		// Ensure player stays within screen bounds
		game.player.x = Math.max(85, Math.min(game.player.x, 1963));
		game.player.y = Math.max(85, Math.min(game.player.y, 2647));
	}
};
// Main game update loop
game.update = function () {
	// Auto-shooting
	if (game.autoShoot) {
		game.autoShootTimer++;
		if (game.autoShootTimer >= 15) {
			// Every 15 frames (4 times per second)
			game.player.shoot();
			game.autoShootTimer = 0;
		}
	}
	// Spawn enemies based on timer
	game.waveTimer++;
	if (!game.bossActive && game.waveTimer >= game.spawnRate) {
		game.waveTimer = 0;
		// Different enemy types based on level
		var types = ['basic'];
		if (game.level >= 2) {
			types.push('shooter');
		}
		if (game.level >= 3) {
			types.push('fast');
		}
		if (game.level >= 5) {
			types.push('tank');
		}
		// Spawn random enemy type
		var type = types[Math.floor(Math.random() * types.length)];
		game.spawnEnemy(type);
		// Occasionally spawn obstacles (10% chance)
		if (Math.random() < 0.1) {
			game.spawnObstacle();
		}
	}
	// Check boss status
	if (game.bossActive) {
		var bossStillActive = false;
		for (var i = 0; i < game.enemies.length; i++) {
			if (game.enemies[i].isBoss) {
				bossStillActive = true;
				break;
			}
		}
		game.bossActive = bossStillActive;
	}
	// Check collisions
	// Player bullets vs enemies
	for (var i = game.playerBullets.length - 1; i >= 0; i--) {
		var bullet = game.playerBullets[i];
		// Skip destroyed bullets
		if (!bullet.parent) {
			game.playerBullets.splice(i, 1);
			continue;
		}
		for (var j = game.enemies.length - 1; j >= 0; j--) {
			var enemy = game.enemies[j];
			// Skip destroyed enemies
			if (!enemy.parent) {
				game.enemies.splice(j, 1);
				continue;
			}
			if (bullet.intersects(enemy)) {
				enemy.takeDamage(bullet.damage);
				bullet.destroy();
				game.playerBullets.splice(i, 1);
				break;
			}
		}
	}
	// Special attacks vs enemies
	for (var i = game.specialAttacks.length - 1; i >= 0; i--) {
		var special = game.specialAttacks[i];
		// Skip destroyed specials
		if (!special.parent) {
			game.specialAttacks.splice(i, 1);
			continue;
		}
		for (var j = game.enemies.length - 1; j >= 0; j--) {
			var enemy = game.enemies[j];
			// Skip destroyed enemies
			if (!enemy.parent) {
				game.enemies.splice(j, 1);
				continue;
			}
			if (special.intersects(enemy)) {
				enemy.takeDamage(special.damage);
			}
		}
		// Special clears enemy bullets too
		for (var j = game.enemyBullets.length - 1; j >= 0; j--) {
			var bullet = game.enemyBullets[j];
			// Skip destroyed bullets
			if (!bullet.parent) {
				game.enemyBullets.splice(j, 1);
				continue;
			}
			if (special.intersects(bullet)) {
				bullet.destroy();
				game.enemyBullets.splice(j, 1);
			}
		}
	}
	// Enemy bullets vs player
	for (var i = game.enemyBullets.length - 1; i >= 0; i--) {
		var bullet = game.enemyBullets[i];
		// Skip destroyed bullets
		if (!bullet.parent) {
			game.enemyBullets.splice(i, 1);
			continue;
		}
		if (bullet.intersects(game.player)) {
			game.player.takeDamage();
			bullet.destroy();
			game.enemyBullets.splice(i, 1);
		}
	}
	// Obstacles vs player
	for (var i = game.obstacles.length - 1; i >= 0; i--) {
		var obstacle = game.obstacles[i];
		// Skip destroyed obstacles
		if (!obstacle.parent) {
			game.obstacles.splice(i, 1);
			continue;
		}
		if (obstacle.intersects(game.player)) {
			game.player.takeDamage();
			obstacle.destroy();
			game.obstacles.splice(i, 1);
		}
	}
	// Powerups vs player
	for (var i = game.powerups.length - 1; i >= 0; i--) {
		var powerup = game.powerups[i];
		// Skip destroyed powerups
		if (!powerup.parent) {
			game.powerups.splice(i, 1);
			continue;
		}
		if (powerup.intersects(game.player)) {
			game.player.collectPowerup(powerup);
			powerup.destroy();
			game.powerups.splice(i, 1);
		}
	}
	// Remove destroyed enemies from array
	for (var i = game.enemies.length - 1; i >= 0; i--) {
		if (!game.enemies[i].parent) {
			game.enemies.splice(i, 1);
		}
	}
	// Update arrays of objects that might be removed
	game.playerBullets = game.playerBullets.filter(function (bullet) {
		return bullet.parent !== null;
	});
	game.enemyBullets = game.enemyBullets.filter(function (bullet) {
		return bullet.parent !== null;
	});
	game.obstacles = game.obstacles.filter(function (obstacle) {
		return obstacle.parent !== null;
	});
	game.powerups = game.powerups.filter(function (powerup) {
		return powerup.parent !== null;
	});
	game.specialAttacks = game.specialAttacks.filter(function (special) {
		return special.parent !== null;
	});
	// Gentle parallax scrolling for background
	background.x -= 0.5;
	if (background.x <= 0) {
		background.x = 1024;
	}
};
// Initialize displays
game.updateScoreDisplay();
game.updateHealthDisplay();
game.updateSpecialMeter();
game.updateLevelDisplay();
// Start background music
LK.playMusic('bgm');