Microsoft held a massive event Tuesday in New York City at which the company unveiled a number of new devices, including the hot Surface Pro 4, new Lumia-branded Windows 10 smartphones with Continuum, and the surprise no one saw coming, the slick Surface Book hybrid laptop. But before any of those new devices were actually shown, Microsoft demoed some exciting new HoloLens mixed-reality technology, dubbed Project X-Ray, that allowed a gamer - named Dan -- to battle holographic robots right on stage, live. During the demo, Dan 'held' a holographic gauntlet gun that he used to fire lasers and blast robots as they hovered in the air or broke through the makeshift walls. Live at the event, onlookers could see what Dan was seeing in his HoloLens augmented reality lenses up on the big screens and the effects and interactions were impressive.