To create Project HoloLens’ images, light particles bounce around millions of times in the so-called light engine of the device. Then the photons enter the goggles’ two lenses, where they ricochet between layers of blue, green and red glass before they reach the back of your eye. “When you get the light to be at the exact angle,” Kipman tells me, “that’s where all the magic comes in.”
Microsoft says that the device "adds holograms to the world around you." The device contains a CPU, a GPU, and a "dedicated holographic processor." The visor can be looked through and it also includes "spatial sound so you can 'hear' holograms behind you." It's slated to be released within the Windows 10 timeframe, which is still a large stretch of time.
How does this related to games? Well...
That's just one possibility of many.