CRT overlay now is a CanvasLayer, that can be put on the viewport over all.

scenes/UI/End.tscn

@@ -1,7 +1,6 @@
-[gd_scene load_steps=3 format=3 uid="uid://8rtse17u7bqg"]
+[gd_scene load_steps=2 format=3 uid="uid://8rtse17u7bqg"]
 
 [ext_resource type="Script" path="res://scripts/End.gd" id="1_0587q"]
-[ext_resource type="PackedScene" uid="uid://cnp8h65468543" path="res://scenes/overlays/crt_overlay.tscn" id="2_teww6"]
 
 [node name="End" type="Control"]
 layout_mode = 3
@@ -36,7 +35,4 @@ layout_mode = 2
 text = "Try again
 "
 
-[node name="CRT_Overlay" parent="." instance=ExtResource("2_teww6")]
-layout_mode = 1
-
 [connection signal="button_up" from="CenterContainer/VBoxContainer/Label2" to="." method="_on_play"]