Claiming a dumbly facetious faux-genre all its own, Kief Davidson and Daniel Junge’s film won’t quite call itself a documentary — it’s done in the gee-whiz style of a factory-tour infomercial, with Jason Bateman narrating. Say hello again to the biggest brand in the toy business, maker of plentifully combinable plastic blocks beloved for their “clutch power.” How to use them is so self-evident that Lego’s community engagement director Tormod Askildsen calls it a language, “more global than English and Windows.” Clearly Lego creativity has many applications, from autism therapy to outsider art to all manner of movie recreations. The name is a contraction of the Danish phrase for “play well,” which partly explains why you don’t see many mini-figures toting guns in official Lego sets, save for distant-historical or fictional contexts. And yet, “It’s so modular,” says one guy who’s done well for himself with a cottage industry of fabricating Lego guns. “They don’t get to decide.” That last part sounds a little hostile, as befits someone whose vocation is answering a weapon-fetish demand in plastic miniature, but his point is well taken. Indeed, after having endured multiple factory fires in the very early years, probably the most pivotal moment in the company’s history was its recent coming around on a generally open-source attitude in matters of set design. Since then there’s been a major building boom, and Davidson and Junge’s film spends its slightly drawn-out duration tracking and cheering on the splendidly various subcultures of Lego enthusiasts. They make some amazing stuff.