How do you guarantee thousands of early adopters for your batty, futuristic augmented reality headset? You promise a chance to enter the world of the most popular video game on the planet. Today, Microsoft announced HoloLens, an augmented reality headset that will fill your home with hovering weather updates and virtual flat screen TVs, but the standout moment of the demonstration involved a man chipping away at the real world and entering the land of Minecraft.

Microsoft acquired Minecraft for $2.5 billion

Microsoft acquired Minecraft and its studio, Mojang, in November of last year for a reported $2.5 billion. (Around the same time, Take-Two CEO Strauss Zelnick saw a presentation of Microsoft's augmented reality technology.) Many critics questioned the high price tag, particularly with the creator of Minecraft departing the company. Now Microsoft's reasoning for the purchase is clear: it has control of a nearly perfect killer app.

Minecraft is available on practically anything with a screen, and while you might expect that to mean the various versions cannibalize one another, the opposite is true. In June of last year, the game's console sales nearly matched home computer sales, with 15 million PC / Mac units, 12 Million Xbox 360 units, and 1.5 million PlayStation 3 units. On mobile, it had sold an estimated 21 million copies. Since then, the game has been available on more hardware, including the Xbox One. As of publishing this piece, the PC / Mac version of the game has been purchased over 18 million times — 9,506 times in the last 24 hours alone. Unlike the vast majority of video games, Minecraft's popularity only seems to grow.

But what makes Minecraft an ideal killer app for a virtual reality headset, or any hardware frankly, is the simplicity of its design and the clarity of its purpose. It doesn't require fast reflexes, complex controls, or expensive development to produce elaborate visuals. It's familiar; it's a planet-sized LEGO set. Newcomers won't be intimidated by the game — if anything they'll be familiar with it. And developers will be able to port the game on the impossibly short timelines required of Day One releases on new platforms.

Minecraft could be the FreeCell of augmented reality

So Minecraft has a huge audience, and it's comparably easy to develop, but here's its big potential: Minecraft could help new users of virtual and augmented reality headsets feel comfortable in three-dimensional space. And that's essential.

There's an urban legend, or maybe it's true, that Microsoft kept the FreeCell experiment in Windows, because it helped new users grow accustomed to using a mouse to communicate with a two-dimensional screen. Remember, what's obvious to us now was, at one point, both miraculous and utterly confusing. Low stress games like chess and FreeCell gave users a fun, relaxing place to inadvertently learn how to better use the Windows interface.

If Minecraft makes HoloLens accessible, it will have been worth its cost

Minecraft could be the FreeCell of augmented reality, or more specifically, HoloLens. Should Microsoft include it pre-installed on every headset, both fans of the game and first-time users will have the opportunity to learn how to engage with its "holographic" objects in a way familiar to practically every child: playing with blocks.

Microsoft's acquisition of Mojang and Minecraft was the singular most expensive purchase of what accounts for a single license. But if it helps to establish of a firm base of early adopters and makes the unquestionably (for the moment) strange experience of wagging your arms in the air while wearing futuristic goggles feel natural, or at least fun, it will have been worth every penny.

And if it doesn't? It still has Minecraft, a game that practically sells itself.