"Office Christmas Party" is an entertaining mess, an acrid but not mean-spirited antidote to the syrupy-sweet cinematic chestnuts of the holiday season. Directors Will Speck and Josh Gordon (2010's "The Switch"), along with writers Dan Mazer (2016's "Bridget Jones's Baby") and Justin Malen and Laura Solon, approach the material with a wicked, bon vivant enthusiasm, tossing cocaine into a snow machine to see how much of it comedically sticks. The R-rated festivities are all over the place—the heaping ensemble is arguably too big and the jokes not always as sharp or spry as they strive—but the film nevertheless diverts and, in its own uniquely salty way, charms.

With Christmas fast approaching and tech company Zenotek facing tough times, irresponsible Chicago branch manager Clay Vanstone (T.J. Miller) is given an ultimatum from his tough-as-nails CEO sister Carol (Jennifer Aniston): land a $14-million contract with potential business partner Walter Davis (Courtney B. Vance), or prepare for massive immediate layoffs. Supported by two colleagues, chief technical officer Josh Parker (Jason Bateman) and lead systems engineer Tracey Hughes (Olivia Munn), Clay goes against Carol's wishes and prepares an anything-goes "non-denominational holiday mixer" as a ploy to win over Walter. Then things get really out of control.

As is apt to occur within the comedy genre, the raucous "Office Christmas Party" hits and misses throughout. It never overstays its welcome or dumbs itself down, though, playing by its own whacked-out rules as the ace actors make the most of their slight yet lively roles. Tops among them is Jennifer Aniston (2016's "Mother's Day"), a droll firecracker as the blunt, unapologetic Carol Vanstone; a blissfully barbed run-in she has with a bratty child at the airport demonstrates the actress' marvelously honed comic timing. Likewise, a scene between Carol and a novice Uber driver (a standout small role from comedian Fortune Feimster) is a highlight.

As protagonists Clay, Josh and Tracey, T.J. Miller (2014's "Transformers: Age of Extinction"), Jason Bateman (2015's "The Gift") and Olivia Munn (2016's "X-Men Apocalypse") bring levity to an outrageous story, a holiday variation on "The Hangover" featuring characters the viewer actually likes and with whom he or she wants to spend time. The talented likes of Kate McKinnon (2016's "Ghostbusters"), as strictly by-the-book HR administrator Mary; Vanessa Bayer (2015's "Trainwreck"), as unlucky-in-love single mom Allison; Courtney B. Vance (2015's "Terminator Genisys"), as the increasingly out-of-control Walter Davis; and Abbey Lee (2016's "The Neon Demon") and Jillian Bell (2015's "Goosebumps"), as escort Savannah and her gun-toting, apple-cheeked pimp Trina, keep the momentum brisk and the good will flowing.

"Office Christmas Party" isn't without contrivances—when Tracey becomes upset with Josh for entertaining a perfectly sensible offer to join Carol's New York branch, it feels particularly strained—but these dips into interpersonal drama don't last long as directors Speck and Gordon look toward their next ridiculous pratfall and tartly amusing situation. Toss in a believably wintry big-city locale and a revolving-door narrative that rarely loses steam, and the film ultimately breaks down one's defenses. True, everything could be just a little bit funnier and a fair bit more focused, but "Office Christmas Party" is nevertheless destined to serve as a winningly acerbic respite for adult viewers looking to relieve their end-of-the-year holiday stresses.