“Is it real?” I ask. I’m looking around at the landscape of Mars, where a dusty, rocky desert stretches in every direction, reddish mountains rising in the distance. It looks so vivid, so strangely plausible that it’s hard to believe that I’m actually looking at the surface of another planet and not the set of a sci-fi movie.

The gentleman who works for Microsoft assure me that it is, in fact, real—depending on how you think about it. I’m currently wearing a prototype version of the HoloLens, a new augmented reality headset announced yesterday by Microsoft, and exploring real three-dimensional images collected from the Mars Curiosity rover using a tool called OnSight.

Unlike VR headsets like the Oculus Rift, the HoloLens only takes up a small part of your field of vision—depending on where you turn your head to look—and uses voice and gesture commands. Although the office around me and the two Microsoft employees next to me are clearly visible in my peripheral vision, so is the holographic world projected in front of it. Wherever I look, Mars appears. In a strange way, they both seem real, two layers of reality coexisting in a way that sounds cacophonous but feels oddly intuitive.

Admittedly, gazing about in three-dimensional space is nothing that the Oculus Rift can’t do—and in many cases, can’t do better, especially since the Rift immerses you in a complete landscape, rather than revealing it piecemeal depending on where you look. But the HoloLens does more, or at least it does it something different.

When I walk towards a nearby desk with a computer, I notice that that Martian landscape disappears beneath it, rather than projecting over it; users can designate areas where they don’t want holograms to appear, which is especially useful if you want to interact with the holograms using a computer. They encourage me to hold the mouse, and when I move the cursor off the screen, it appears suddenly within the holograph as though the Martian landscape has become an extension of my desktop.

Suddenly, a man appears on the Martian plain. Or at least, the shape of a man appears, a featureless avatar who announces that he’s from NASA. “Is he real?” I ask. He promises me that he is—that I’m speaking live to a member of the NASA team that Microsoft has been working with to develop this program, which will allow JPL to explore the data they collect from the Rover collaboratively, interactively and three-dimensionally.

Despite augmented reality’s reputation for faint, shuddering images, everything I was seeing through the HoloLens was surprisingly crisp and offered little lag. The man points out a distant rock, and suggests that I tag it, so that the Rover can analyze it with its ChemCam laser, something he says NASA will actually be able to do via the HoloLens. I hold my arm out within my field of vision, lifting and retracting my index finger like that little kid from The Shining, a gesture they call air-tapping. It plants a flag on Mars.

In the next demo, we’re introduced to HoloStudio, a program for building 3D objects. While one man gives a quick speech about the finer points of the tool, another stands in the middle of the room, pointing and moving his fingers in empty space, like he’s conducting an invisible orchestra. On several nearby screens, we get to see what he’s “really” doing: building a three-dimensional koala with a jetpack from a series of preset shapes that he shrinks, enlarges, copies, pastes and colors. Eventually, he says, you’ll be able to send whatever you build off for 3D printing with a click of a button, and receive it in the mail with the ease of an Amazon package.

When he finishes with his creation, the man wearing the HoloLens digitally picks the koala in his hands and set it down on a nearby couch, right next to a 3D printed car that was also designed in HoloStudio. Shortly afterwards, the man walks over to the couch, moves the car out of the way, and sits down. For a moment I feel disoriented, like the muscles of my brain are stretching in an unfamiliar way. Why did he move the car and not the koala? I wonder for a moment. Because the car is real, and the koala isn’t, I remind myself.

There’s something about the HoloLens experience that seems to blur these edges between real and unreal in strange and sometimes exciting ways. Unlike VR headsets, which plunge you wholesale into an immersive and completely different world, the HoloLens feels more like shining a digital spotlight—directed by your gaze—that scrapes away the real world and reveals a new one glimmering underneath it.

Perhaps the most exciting development for gamers is the HoloLens version of Minecraft, currently referred to as HoloBuilder. The HoloLens has the ability scan a room to map objects and surfaces, turning the world around you into the terrain of the game. After donning the headset again for the HoloBuilder demo, a gentleman from Microsoft suggests that I look under a nearby coffee table. When I kneel down and peer beneath, a charming little Minecraft castle reveals itself. Shadows—presumably from the table above—cover the castle, and I drop a little redstone torch beside a man on the drawbridge. The area around him fills with light.

I notice a small band of Minecraft zombies lurking nearby, and decide that it’s time for them to die. “Shovel,” I say, and the cursor transforms into a digging tool. Before my Microsoft guides can give me further instructions, I click a block beneath one of the zombies, and he disappear through the hole like I’ve opened up a trap door beneath him. I laugh. What I’m actually supposed to do, however, is switch tools and drop a torch near several blocks of dynamite, setting off a chain reaction and blowing all the zombies to hell. I happily oblige. Shortly after the explosion, a virtual lacuna opens up in the coffee table; when I walk closer and peer downward, I see the zombies tumbling into a sea of lava.

I’m enchanted. I want to plop down, sit cross-legged on the floor and play for hours with the secret world that I just discovered, but the time allotted for the HoloBuilder demo is tragically brief. My Microsoft guide directs my attention elsewhere (and with the HoloLens, directing someone’s attention feels a bit like pointing them to the X on a treasure map). I find three blocks of dynamite affixed to the wall, almost like little curios. Naturally, I blow them up.

As the wall detonates, bats fly out from the breach directly towards my face. The Microsoft reps tell me that the HoloLens has spatial audio, “so we can hear holograms even when they are behind us.” Which, P.S., is a creepy thing to say.

More interesting than the bats, however, is what the explosion leaves behind: a digital breach in the wall that seems to open up a window into a whole other little world lined with veins of ore. I want to keep going, digging deep into the wall to find out what other treasures it contains, but the men from Microsoft politely inform me that there isn’t time. Reluctantly, I walk back to the chair where they will reclaim the HoloLens, dropping as many torches as I can en route with frantic Redrum gestures.

When I describe HoloBuilder to my roommate after the Microsoft event, she tells me about how much she loved to build vast Lego worlds as a child, her blocky civilization slowly spreading over couches, tables and every other surface in her home that she could find. Eventually, when her worlds grew too vast—and the danger of a bare foot stepping painfully on a Lego block too great—her parents would tell her it was time to pack them up and put them away.

“What if I could have built them digitally and kept them forever?” she asks. She’s not a gamer, but she seems excited too. And what if you could have shared them your friends? I ask. We agree that this would have been amazing. And, really, it still is. Minecraft has proved hugely popular for gamers young and older, experienced and inexperienced—and plenty of people who might not consider themselves gamers at all. If HoloBuilder can live up to the promise of its simple, endlessly engaging 2D sibling—and the promise of the HoloLens itself—this could be the game that makes it worth buying.

Augmented reality isn’t an experience that would mesh well with a lot of traditional games—I can’t imagine wanting to play Call of Duty on a HoloLens, for example. But there’s something about HoloBuilder that offers an almost archaeological sense of discovery, the same sense of magic that makes fantasy tales like Harry Potter so irresistible: the feeling that incredible and fantastical things might lie buried beneath the boring veneer of the “real” world, waiting to be discovered by someone with the power to see what others can’t.

Perhaps the most native HoloLens experience—or the one that demonstrates its unique abilities— is the holographic Skype call I make in another demo. The neat rectangle of his video feed follows me around wherever I look as though it’s tethered to my gaze, though I can pin it down to a static point with a quick airtap.

The man tells me that he can see everything that I see, and that he wants to help me install a light switch. There’s a mess of (real) wires coming out of the (real) wall, and an array of (real) tools on the table beside me. He instructs me to pick a voltage tester, and when I hesitate for a moment, he draws a bright green holographic arrow across my field of vision to point it out. A moment later he erases the arrow, and sketches out a quick diagram directly on the items he wants me to manipulate: which wires to connect, and where to connect them.

I’m reminded for a moment of the game Keep Talking and No One Explodes, where a player is given a manual for an explosive device and must verbally guide another playing wearing an Oculus Rift through defusing a bomb while a timer counts down. My helpful Skype friend floats around my field of vision like a heads-up display and prompts me with useful tips to solve this puzzle like a cross between Clippy and Navi. When we’re finished, he tells me to pick up a small controller and turn on the light. I push the button, and the circular lamp above me glows brightly in a gleaming ring.

“Is it real?” I ask. For a moment, I’m not even sure what I mean. Was the electrical circuit that I created real? Is the light shining down on me real? Was the experience real? The men from Microsoft assure me that it was.