Add a background

godot/scenes/main.tscn

@@ -44,6 +44,13 @@ points = PoolVector2Array( 0, 0, 40, 0, 40, 20, 0, 20 )
 
 [node name="Root" type="Node"]
 
+[node name="Background" type="Panel" parent="."]
+margin_right = 400.0
+margin_bottom = 400.0
+__meta__ = {
+"_edit_use_anchors_": false
+}
+
 [node name="Walls" type="StaticBody2D" parent="."]
 collision_layer = 2
 physics_material_override = SubResource( 1 )