In its second weekend, “A Minecraft Movie” built on its success with a blockbuster $80 million haul, holding strong at the top of the box office. So far, it has grossed $281 million domestically and $550 million worldwide. But what is “Mindcraft?” Since launching in 2009, Minecraft has quietly become one of the best-selling video games ever—no guns, no gore, just endless creativity. With over 91 million monthly players, it's a global phenomenon. To get to the bottom of the blocky craze, David Po