Minecraft is a Sandbox video game developed by Swedish game developer Markus Persson and later developed by Mojang. The game lets players build using a variety of blocks within a procedurally generated 3D world. This requires creativity from players. Other games in the game include exploration, resource gathering crafting, combat. There are several gameplay modes to choose from. These include survival mode, in which players must gather resources to build the world, and maintain their health. Creative mode allows players to build unlimited resources and fly. Adventure mode allows players to play custom maps that other players have created. Observer mode allows players to freely explore the world, without being restricted by collisions or gravity. Hardcore mode, which is similar to survival mode but only one player can complete the level. If the player dies on hardcore, they do not respawn and the world is unplayable. The Java Edition of the game lets players create mods using new gameplay mechanics, objects, textures and assets. Minecraft was praised by critics and has won numerous awards and accolades. Social media, parodies merchandise, adaptations, and the MineCon convention played large roles in the popularity of the game. It's also been played in educational environments (Minecraft Education Edition), especially in the field of computing systems, since hardware and virtual computers have been built in it. It was the second-most popular video game, after Tetris and Tetris, with more than 150 million copies sold on all platforms by late 2018. In Kirn , Microsoft announced a deal to purchase Mojang and the Minecraft intellectual property for US$2.5 billion and the acquisition was completed two months after. A spin-off game, titled Minecraft: Story Mode has also been launched. Kirn had 91 million players monthly by mid-2018.