When last I saw and wore the HoloLens it felt very much like a collection of hacked together tech. It was so fragile, I was told, that I couldn't touch the headset, and its self-contained computer was actually in a block of electronics hanging noisily around my neck.

In action, it was stunning, different than other forms of augmented and virtual reality I had seen.

Today, sitting down in Microsoft's second-floor, air-conditioned meeting rooms on the E3 show floor, I was reintroduced to the HoloLens, and it's grown up a lot.

Now the device is fully self-contained, with a computer powerful enough to run Windows 10 games and programs silently tucked away in a relatively sleek looking headset. The experience was no longer hands off and I no longer had to wear what the developers nicknamed the "Flavor Flav necklace" to power the unit.

It weighed very little and, once activated, created a high-definition image that seemed to float in space before my eyes, or lock onto walls or tables. The virtual screen was about the size of a deck of cards if you held it in front of your eyes with your arm half-extended. It sounds small, and in some cases, including once you first put it on, it looks small. But once you get into the experience of playing a game with it, the size issue seems to fade away.

Once you get into the experience of playing a game, the size issue seems to fade away.

Microsoft invited me into the makeshift office, a roughly 13-by-13-foot room complete with tiny couches, and paintings hanging on the walls, to give me a chance to play something they're calling Project X-Ray.

Project X-Ray isn't meant to be a prototype for an upcoming game, instead a spokesman described it to me as an "exploration for gaming in a mixed reality-environment. It's designed to explore what's possible when you have a device that's untethered from a computer. What gaming could look like on a HoloLens."

The game was fairly simple. Players put on the headset and hold an Xbox One controller in their hands. A targeting reticle is controlled by what you're looking at and you can fire a sort of rail-gun with the right trigger and activate an ability that lets you see enemies through walls and slow down time with the left trigger.

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The object of the game is to survive an attack of bug-like aliens that are breaking through the real walls of the room you're in, by shooting them and avoiding their return fire and lasers.

You take damage in the game when a shot hits your head, but other than that one tweak, the game plays like a stripped down first-person shooter.

The game was a fun demo designed to show off the capabilities of the HoloLens. The targeting reticle was a floating circle with a split outer ring that showed my armor level and how charged my special ability was. Floating arrows indicated where the enemies were.

Quickly into the game play I found myself ducking and dodging to avoid incoming fire from the aliens I hadn't killed immediately. It wasn't the sort of game one could play in a den with a coffee table or dogs nearby, but because it was augmented reality, had there been things in the way, I could have simply avoided them.

The bugs would break through the wall, leaving behind a hole that showed the faked inner structure of the office. Sometimes I saw wood framing, or brick, sometimes I could see deeper into the wall. It was a neat effect.

The game felt like the sort that shipped with the Wii, back when Nintendo was initially trying to train people on how to use their new technology. While the developers said this was just to show of the HoloLens' possibilities, it certainly looked like the sort of demo that might ship with the still unpriced, undated heaadset.

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