"Madea's Big Happy Family" isn't the worst film to feature that law-breaking, right-and-ready, tell-it-exactly-like-it-is matriarch, but it is the sloppiest. Once again written and directed by Tyler Perry (2009's "I Can Do Bad All By Myself"), this whiplash-inducing parade of broad, humor-based caricatures and soapy melodramatic histrionics pushes too far in both tonally disparate directions for either one to work. It's all kinds of a garish charade—a shame since it is anchored by a touchingly vulnerable performance by Loretta Devine (2011's "Jumping the Broom").

When Shirley (Loretta Devine) is diagnosed with brain cancer, she begins to bravely prepare herself for the end of her life. When she invites her three grown children over to break the news to them, they are so involved in their own selfish worlds that there is no time to collectively have a heart-to-heart with them. Kimberly (Shannon Kane) is cold and controlling, a real estate agent who has tried to separate herself from her working-class upbringing. Tammy (Natalie Desselle Reid) has two disrespectful sons and a husband, Harold (Rodney Perry), whom she is constantly walking all over. Youngest Byron (Shad 'Bow Wow' Moss), who shares an infant son with the belittling Sabrina (Teyena Taylor), is considering going back to drug-dealing to please his materialistic new girlfriend, Renee (Lauren London). They're all rather monstrous in their current forms, and Shirley's family friend, Madea (Tyler Perry), doesn't like the way they've been treating their mother one bit. By reuniting them for a long-time-coming family dinner, Madea hopes Shirley and her kids can resolve their issues and come together as a family before it's too late.

"Madea's Big Happy Family" showboats as comedy but is really, really dark beyond Madea's and Aunt Bam's (Cassi Davis) feisty one-liners. True to form for Tyler Perry, there are family secrets exposed, tyrannical supporting players, and a big heaping of Jesus to soften the harder edges. Madea slaps around some misbehaving kids and crashes her car through a restaurant after getting talked back to in the drive-thru. Is there any criminal repercussions for this behavior? No. Loretta Devine is moving as Shirley, and Tamela J. Mann, reprising her role as Madea's daughter, Cora, has a warm, appealing presence. By contrast, Shirley's three kids—and, for that matter, Byron's awful ex and even more awful new beau—are so enormously unpleasant that it's difficult to sympathize with them even after they've realized the error of their ways. Ending the movie with a spoof of "The Maury Povich Show" doesn't at all gel with the sobering plot developments in the third act. "Madea's Big Happy Family" is a facetious title; there's not a happy one in the bunch. Eventually, neither is the viewer.