Minecraft starts off, in the single-player mode, as a game about survival. Alone and empty-handed, stranded in a retro-cubist 3D landscape with a first-person perspective, you have to gather resources, make tools, and build a shelter before the safety of daylight passes into the danger of night, when monsters prowl. It's a tense and desperate experience, especially when you're new to the game and trying to figure out how it works as the sun sinks toward the horizon.
The tension arises purely out of the mechanics. There's no plot or pre-authored story, no voice over the radio telling you where to go, not even a map in the corner of the screen showing your location. Minecraft is a sandbox, a game of unexpected experiences emerging out of the actions of the player within some basic rules.
Once you grow accustomed to the rhythm of day and night and learn to deal with the monsters, the game becomes much more than sandbox survival. While still interspersed with moments of extreme tension, it becomes more of a quiet, contemplative, and occasionally awe-inspiring experience focused on exploration and creation. Despite its deliberately primitive graphics, Minecraft generates surprisingly beautiful vistas, and a surprising variety of terrain - from forests to swamps to deserts to tundra. Beneath the surface are labyrinthine cavern systems, filled with monsters and rare treasures such as diamonds and gold.
Rather than presenting you with a living world and asking you to empty it of life, as many video games do, Minecraft offers a canvas and the raw materials to constuct your own architectural fantasies: towering castles, vast underground complexes, dense networks of roads. Architecture, and the structuring of space, is the most visible and physical evidence of society; it is no coincidence that games about crafting a new order from an undeveloped world, such as SimCity and Civilization, center on architecture.