Slant Magazine:
Cyrus peaks in its first half and then slowly tails off, and even if it compensates for this decline by focusing more squarely during its third act on its characters' emotional turmoil, that shift serves to reinforce the narrower but still-present disconnect between humor and drama that remains in the Duplasses' work. Nonetheless, when fully engaged with the process of being funny, the film can be a riot, thanks in part to a rapport between Reilly and Hill that's teeming with over-the-top seething resentment. Reilly's tall, curly haired, slightly disheveled, and spastic John is a perfect foil for Hill's squat, portly, neatly dressed, and methodically composed Cyrus, and their shared intensity—barely concealed beneath placid demeanors meant to please Molly—is the energy that drives the proceedings.
