correctly delete old rooms

Assets/Engine/Runtime/Engine.cs

@@ -116,11 +116,25 @@ namespace EscapeRoomEngine.Engine.Runtime
             room.AddSpace(space, exit);
         }
 
-        public void HidePreviousRoom()
+        public void HidePreviousRoom(bool destroy = true)
         {
-            if (NumberOfRooms > 1)
+            if (NumberOfRooms > 2)
             {
-                _rooms[NumberOfRooms - 2].roomObject.SetActive(false);
+                var room = _rooms[NumberOfRooms - 3];
+                
+                // lock the doors that might be used to return to the old room
+                room.exit.toIn.DoorState.Lock();
+                room.exit.fromOut.DoorState.Lock();
+
+                // destroy or hide the old room
+                if (destroy)
+                {
+                    Destroy(room.roomObject);
+                }
+                else
+                {
+                    room.roomObject.SetActive(false);
+                }
             }
         }