Player gun, bullet and its collisiions. Refactor.

metroidvania/Utils.gd

@@ -0,0 +1,8 @@
+extends Node
+
+func instance_scene_on_main(scene, position):
+	var main = get_tree().current_scene
+	var instance = scene.instance()
+	main.add_child(instance)
+	instance.global_position = position
+	return instance