feat: Implement core game mechanics including player, enemies, bullets, HUD, and level setup.

scripts/bullet.gd

@@ -0,0 +1,44 @@
+extends Area2D
+
+@export var speed: float = 500.0
+@export var lifetime: float = 2.0
+@export var damage: float = 10.0
+@export_enum("AP", "HE") var ammo_type: int = 0
+@export var explosion_radius: float = 100.0
+var shooter_group: String = "player"
+
+func _ready():
+	# Connect collision signal
+	body_entered.connect(_on_body_entered)
+	
+	# Delete bullet after lifetime seconds
+	await get_tree().create_timer(lifetime).timeout
+	queue_free()
+
+func _physics_process(delta):
+	position += Vector2.RIGHT.rotated(rotation) * speed * delta
+
+func _on_body_entered(body):
+	if body.is_in_group(shooter_group):
+		return
+
+	if ammo_type == 0: # AP
+		if body.has_method("take_damage"):
+			body.take_damage(damage)
+	elif ammo_type == 1: # HE
+		explode()
+	
+	queue_free()
+
+func explode():
+	# Visual effect could go here
+	# Find all potential targets
+	# If shooter is player, target enemies. If shooter is enemy, target player.
+	var target_group = "enemy" if shooter_group == "player" else "player"
+	var targets = get_tree().get_nodes_in_group(target_group)
+	
+	for target in targets:
+		var distance = global_position.distance_to(target.global_position)
+		if distance <= explosion_radius:
+			if target.has_method("take_damage"):
+				target.take_damage(damage)