Is it possible to get node of a *.tscn

jonSS my player node script is kind of full

What do you mean by "full"? Just add this function to existing code. Having it in top node is better design-wise, and calling it looks simpler.

Your setup is kind of strange with Player being a sole autoload. It could be fully automated if level scenes were instantiated manually. This way, somebody needs to notify the autoload that scene was swapped so it can adapt itself to the new scene.

You don't need different scripts for each level. Use the same script just export the properties like map_POS and adjust them in editor. With this, you don't have to type any new code regarding camera/player initialization when you create a new level scene. It's fully automatic.

jonSS There's a way to do it without using scripts in levels, from the same place you change the scene. You can pass player position to Player.level_started() and call it deferred from next_level scene:
in player.gd:

func level_started(player_pos: Vector2):
	var lvl = get_tree().get_current_scene().get_child(0);
	position = player_pos
	cam2D.limit_right = lvl.get_region_rect().size.x;
	cam2D.limit_bottom = lvl.get_region_rect().size.y;

In next_level.gd:

if ( levelGO == true ):
	levelGO = false;
	get_tree().change_scene_to_file(nextLevel);
	Player.call_deferred("level_started", Vector2(plrnextX, plrnextY))

This is then minimal intervention into your existing setup and it's more or less fully automated. You can as well add other arguments to level_started() if needed.

jonSS Try it in 4.1. It works fine.
It's something related to 4.2, it's still beta after all but I'm not sure if it's a bug or they changed something in deferred call order. In any case the current_scene shouldn't be null there.

jonSS I'm not following what they're doing with 4.2 but the problem is happening when calling change_scene_to_file() from either _process() or _physics_process():

func _process(delta):
	if Input.is_action_just_pressed("ui_accept"):
		print(get_tree())
		get_tree().change_scene_to_file("res://scene2.tscn")
		print(get_tree())

The scene gets properly changed but get_tree() returns null after the call. When doing this from _ready() everything is as expected. Looks like a bug.

jonSS I reported it. The devs confirmed it as a regression bug that appeared in dev2. They added it to 4.2 milestone, so it'll surely be fixed.

As for your project, It'd be best to temporarily go back to 4.1 and use my last suggested solution with call_deferred() from next_level.

jonSS The solution with deferred call I suggested works perfectly. It's fully automatic and, design-wise, it's a "natural" way to do it in your setup.

get_tree() doesn't work in 4.2 because of a core engine bug. The moral of the story is that you shouldn't quickly jump into using latest betas if're not well acquainted with engine's inner workings.

jonSS Hm, the plot thickens Devs now claim that this timing change in change_scene_to_file() is in fact intentional. It won't be a deferred call from 4.2 on. It'll behave just like remove_child(), taking place immediately. The node running the script will not be in the scene tree after the call, so naturally get_tree() will return null. Imho this is better than it being deferred but it somewhat changes the way to handle scene swapping in cases like yours.

To make things bulletproof you should set things up so that there's no reliance on exact scene change timing:

• put all data that's relevant to camera/player initial setup into the level scene itself (instead into transitional next_level scene)
• notify the Player autoload about scene change form level itself by calling a dedicated level_started() function from level's _ready().
• do all level-related initialization of camera/player in that level_started() function.

That's all there is to it. If you set it up properly, this is fully automatic and should work regardless of change_scene_to_file() being deferred (v 4.1) or not (v 4.2)