Can 100 million users—the number who had signed up to play Minecraft as of February—be wrong? Probably. But there came an hour, a paternal hour, when I had to find out what was going on. To seek the source of the attraction, if it had a source. So I went for it. All thumbs, my skin crawling with tech-repulsion, I entered Minecraft.

The game was created, invented, whapped into being by a Swedish game designer named Markus Persson but known to his fan-horde as Notch. It is a sandbox game, which means that—unlike, say, Pac-Man—the player is not trapped in a deterministic nightmare of pursuit and predation. Rather, he or she roams, a digital flaneur, essentially creating his or her own game. Algorithmic “terrain generation” is the key here. As you plod or swim or fly across one of the Minecraft biomes—desert, snowy mountain, undersea labyrinth, freaky horticultural terrace—it builds itself out before you. Steppes, caves, mesas of recombinant pixels, on and on. Those images that yet / Fresh images beget, as that champion gamer W. B. Yeats once wrote. All quite unbeautiful and blocky, just squares upon squares, but somehow quite winning in their nonrealism, everything corrugated with a benign fictive pressure. I jumped in, moved around, and as the vision rippled into structure and novelty at its edges I got a fleeting whiff of my son’s neuroplastic brainpower, the learning-crackle of the young minecrafter. There is a rim to Minecraft, if you roam far enough—a place in some versions of the game where the internal mathematics get stretched and things start to go buggy. But so few people make the trip that it remains largely theoretical. Doesn’t it sound like our own universe, though? Psychedelic wobbles at the outer edge?

As for what you do in Minecraft—well, you mine, and you craft. Which is to say, you obtain and stockpile materials—wood, stone, metal, dirt—and you build stuff from them. You build for fun, and you build (if you’re playing the game in “survival mode”) because of the hostile mobs: the zombies, creepers, skeletons, and other nasties who will take your life in the night if you are not structurally protected. This is the Jungian under-rhythm of Minecraft: after 10 minutes of game-play in daylight, you get twilight, and then seven minutes of game-play at night. Peril and dimness. Exposure. Rain, sometimes, which is very upsetting. So in the failing light you build, build. You get wood by punching or hacking at trees, and dirt by thumping the ground. (But don’t dig down too far, or you’ll be consumed by lava.) One doomy Minecraft dusk, plugged almost fatally by arrows twanged from the bows of skeletons, in haste I lumped together a few dirt walls. Then I waited, full of holes. Would morning never come?

You can build anything you want, to the limit of your building skills, manipulating the simple cubes into endless complication. Building is what it’s all about, if you ask the kids. Building, and now and again destroying. My son and his Minecraft colleagues—you can play in a solo world, or in one teeming with other players—are always gaily torching one another’s houses or blowing them up. Huge crates of TNT can be manufactured, if you have the patience, with biblical impact: you can level a mountain. But always the direction of the game is toward more building, greater complexity, higher levels of personalization.