refactor structure

scenes/game/game.gd

@@ -0,0 +1,27 @@
+extends Node
+
+@onready var back_button: Button = $BackButtonContainer/BackButton
+const MATCH3_SCENE_PATH := "res://scenes/match3/match3.tscn"
+var match3_instance: Node
+
+func _ready() -> void:
+	if not back_button.pressed.is_connected(_on_back_button_pressed):
+		back_button.pressed.connect(_on_back_button_pressed)
+	_load_match3_scene()
+
+
+func _on_back_button_pressed() -> void:
+	AudioManager.play_ui_click()
+	GameManager.save_game()
+	if match3_instance and is_instance_valid(match3_instance):
+		match3_instance.queue_free()
+	GameManager.exit_to_main_menu()
+
+func _load_match3_scene() -> void:
+	var match3_scene := load(MATCH3_SCENE_PATH)
+	if not match3_scene or not match3_scene is PackedScene:
+		push_error("Failed to load Match3 scene at: %s" % MATCH3_SCENE_PATH)
+		return
+
+	match3_instance = match3_scene.instantiate()
+	add_child(match3_instance)