Fixed debugger errors in many files and optimized some scenes/code

GUI/Countdown Timer.gd

@@ -1,6 +1,6 @@
 extends Label
 
-signal timer_end
+signal timer_out
 
 
 func _process(_delta: float) -> void:
@@ -8,5 +8,5 @@ func _process(_delta: float) -> void:
     set_text('%02d:%02d' % [time_seconds, int(($Timer.get_time_left() - time_seconds) * 100)])
 
     if $Timer.get_time_left() == 0:
-        get_tree().change_scene('res://Levels/Hub World.tscn')
+        emit_signal('timer_out')
     return