Add the Atom arena

Game.tscn

@@ -5,7 +5,7 @@
 
 [node name="Game" type="Node2D"]
 script = ExtResource( 3 )
-levelNames = [ "Square", "Lab", "Focus" ]
+levelNames = [ "Square", "Lab", "Focus", "Atom", "template" ]
 
 [node name="MainCamera" type="Camera2D" parent="."]
 position = Vector2( 500, -500 )