With 2005’s The Puffy Chair and 2008’s Baghead, writers/directors/brothers Mark and Jay Duplass established themselves as standard-bearers for the 21st-century film genre saddled with the just-
appropriate-enough-to-stick tag “mumblecore.” In this world of handheld cameras, natural lighting, and plots that coagulate around a series of casual, seemingly unscripted conversations, the Duplasses flourished on both sides of the camera, with Mark delivering sharp lead performances in his own films and others’—most notably, Lynn Shelton’s celebrated bromance Humpday. So it makes sense that the first Hollywood-mumblecore hybrid should be a product of the brothers Duplass.
Cyrus is that product, and the first Duplass brothers film not starring a Duplass brother. Instead, the cast is stacked with well-known Hollywood actors—John C. Reilly, Marisa Tomei, Jonah Hill, Catherine Keener—all of whom commit themselves to the “hang out and say things” aesthetic with imagination and pizzazz. The plot: A stuck-in-a-rut divorcé (Reilly) strikes up a promising new relationship with a hot, fun woman (Tomei) who is inordinately devoted to her live-at-home loner of a son (Hill). Thus commences the dance of Cyrus, as this trio of characters rubs up against each other and the itchy sparks fly.
For its first hour, Cyrus bumps along most entertainingly, as the audience pieces together the cryptic backstory—a key shot features a framed photo of Tomei’s character breast-feeding what looks like a fifth-grade boy—and the actors relish the casual freedom. What makes mumblecore worth mentioning is the genre’s insistence that seemingly mundane human behavior can be as exciting as a bus explosion, and Cyrus‘s movie-star cast makes the most of the restricted situation, especially Tomei, a premature Oscar winner who’s retroactively earned her award via golden supporting performances such as this.
Unfortunately, things get iffy in the home stretch—a not-unusual problem for mumblecore, where final scenes can throw a whole seemingly meandering story into focus or just taper off with a dull thud. In Cyrus, the Duplasses strive for a messy happy ending but deliver an abrupt thud, which feels as much about the stars’ competing schedules as it does about anything connected to the characters. It’s an unfortunately klutzy end to a largely winning experiment. 
no one’s commented yet? review is spot on, especially about the abrupt ending.
the trailers make it look like a comedy with a story, but it’s a story with awkward comedic moments sprinkled throughout.
I actually thought it was funny throughout, but completely agree about the ending. *Spoiler alert* It didn’t make sense that Jonah Hill’s character suddenly just realized he was crazy and apologized for everything. Part of what makes someone like Cyrus crazy is a lack of self-awareness that prevents the person from ever taking accountability for the all shit they pull.