Sencillisimo GDScript, lo que entra dentro de un Area3d, borra todos sus hijos; todo su contenido;

 extends Area3D

# Called when the node enters the scene tree for the first time.

func _ready() -> void:

pass # Replace with function body.

# Called every frame. 'delta' is the elapsed time since the previous frame.

func _process(delta: float) -> void:

pass

func _on_area_entered(area: Area3D) -> void:

queue_free()

pass # Replace with function body.