The movie isn't perfect and viewers without a knowledge of the scene might struggle at points, particularly with some of the game footage as a couple of the fights simply appear chaotic rather than complex. Early in the documentary it's explained that players make calculations and deal with a great number of variables every second so dissecting a dramatic sequence or a skilful snippet of play might have helped convey that complexity in a more manageable form. If you do know more about the game, you'll know the winners and losers in advance meaning some of the interviews can be jarring.
Above all, though, it's a movie which participates in, as well as documents, a tipping point. The movie is set largely in 2011 and over the last two years eSports and professional gaming have made real inroads in terms of being considered an occupation where they were previously often dismissed as a childish hobby.