Viewports

 

1.  Engine: Blender Game
  • Info menu >> Render Engine box >> Blender Game
Note:
  •  There are menus that are only available when The Blender Game render engine is selected.
2.  Select Camera
  • 3D View menu >> View >> Cameras >> Active Camera
3.  Give camera a unique name
  • Properties menu >> Object tab >> Cam1

Note:
  • I'm naming the first camera:  Cam1