Mission One – Future Proofing the Code - Creating E-Learning Games with Unity - page 102

Note
If you have Unity3D Pro, you can replace Applica-
tion.LoadLevelAdditive() with Applica-
tion.LoadLevelAdditiveAsync() , which will make the level transition ap-
pear smoother for large levels (since it doesn't block the renderer). If you acci-
dentally use LoadLevelAsync() or LoadLevel() , you will find that the ob-
jects that were previously loaded will be deleted when the new level loads up
(possibly _global and its children in our case).
Congratulations! We now have written a game state manager class GameMgr , which
uses the mediator pattern to selective load scene files that correspond to different
levels in our game.