There are prolific filmmakers–Woody Allen famously cranks out a new movie each year–and then there’s Joe Swanberg, who makes everyone else who has ever stepped behind a camera seem like a slacker. Since 2005, the 32-year-old has directed, written and produced 17 films, often starring in them and in some instances serving as his own cinematographer. Once synonymous with the Mumblecore movement, Swanberg continues to evolve with Happy Christmas, a consistently surprising comedy that reunites him with his Drinking Buddies star Anna Kendrick, here cast against type as an irresponsible, down-on-her-luck young woman, who imposes on her brother (Swanberg) and his wife (Melanie Lynskey), and disrupts their domestic tranquility.