Minecraft is a sandbox-building independent video game written in Java originally by Swedish creator Markus "Notch" Persson and now by his company, Mojang, formed from the proceeds of the game. It was released as an alpha on May 17, 2009, with a beta version on December 20, 2010. Official releases for iOS and Android have been released and the full version of the PC game was released on November 18, 2011 at MineCon 2011. The Android release was temporarily exclusive to the Xperia Play but is now available to the rest of the Android market. A version of the game for the Xbox 360 with Kinect support is under development by 4J Studios and delayed until 2012. Minecraft is focused on creativity and building, allowing players to build constructions out of textured cubes in a 3D world. Gameplay in its commercial release has two principal modes: Survival, which requires players to acquire resources themselves and maintain their health and hunger; and Creative, where the player has an unlimited supply of resources, the ability to fly, and no concept of health or hunger. A third gameplay mode, named Hardcore, ratchets up the difficulty of surviving and forces the player to delete his or her world upon death. An outdated Classic version is also available for free, although it is no longer being developed. Creative Minecraft resembles Classic, but with many more features. The gameplay is heavily inspired by Infiniminer by Zachtronics Industries, and Dwarf Fortress by Bay 12 Games. The game was officially released at MineCon on November 18, 2011. Minecraft was developed for about a week before its public release on May 17, 2009, on the TIGSource forums, where it gained a considerable level of popularity. It has been continually updated and patched since then, and while it was still in alpha release, it garnered several hundred thousand sales and received critical notice and acclaim from many reviewers. It passed a million units sold on January 12, 2011, less than a month after reaching Beta. By November 7, 2011, the game had sold 4 million units.
A screenshot of a randomly generated Minecraft terrain The core gameplay revolves around construction. The game world is essentially made of cubical blocks arranged in a fixed grid pattern which represent different materials, such as dirt, stone, various ores, water, and tree trunks. While the players can move freely across the world, objects and items can only be placed at fixed locations relative to the grid. The player can gather these material "blocks" and place them elsewhere, thus potentially creating various constructions. Minecraft has three currently available gameplay modes, Survival, Hardcore and Creative. Classic is the earliest free version and initially featured only creative game mode with only building (block placement and removal) aspects of the game and unlimited block supply. The game was then split into single-player survival mode (referred to as "Survival Mode Test"), which contained monsters and a much greater variety of blocks and items available, as well as requiring players to mine their own blocks. The game starts by placing the player on the surface of a huge procedurally generated game world. The player can walk across the terrain consisting of plains, mountains, caves, and various water bodies. The world is also divided into biomes ranging from deserts to snowfields. The in-game time system follows a day and night cycle. Throughout the course of the game the player encounters various non-human creatures, referred to as mobs. During the daytime, non-hostile animals spawn, which can be hunted for food and crafting materials. Hostile monsters, such as large spiders, skeletons, zombies and the dangerous exploding "creeper" will spawn in unlit areas, such as in caves or during the night.