Neighbors (which, by the way, is not a remake of the 1981 Dan Aykroyd / John Belushi movie) follows Mac (Rogen) and Kelly Radner (Rose Byrne), who have just leveraged their last dollar for a nice house in a suburban neighborhood in which to raise their newborn daughter. Days after they move in, however, they discover the house next door has been sold as well...to a notorious frat from the nearby college. Mac and Kelly attempt to make peace with the frat leader, Teddy Sanders (Zac Efron), but his determination to throw the most epic party in the chapter's history quickly puts the two homes on a collision course. Before long, they're embroiled in all-out war, with Mac and Kelly hoping to trick the frat into violating their final strike with the college dean (Lisa Kudrow).

Although the film (written by Andrew J. Cohen and Brendan O'Brien, and directed by Forgetting Sarah Marshall's Nicholas Stoller) appears to strive toward a bit more structure than the on-the-fly tone of most modern comedies, the film struggles to stay focused, not just on its characters but even its basic premise. The battle starts and stops somewhat arbitrarily, at one point spurred on simply because Mac notices Teddy and friends having a barbecue. Instead of organically setting up a scene where Kelly comes up with a plan of attack, there's an awkward 20-second scene of her watching "The Office" that pops in out of nowhere. The film plays with the idea that Mac and Kelly are insecure about coming the "uncool adults", and some of their willingness to pick a fight comes out of their domestic antsiness, but the editing still feels jumpy, and the tone of many of these scenes has a sitcom-ish, PG-13 softness that clashes with the rest of the film's R-rated cartoonishness.

Some of that cartoonishness is very funny. A fight between Teddy and his BFF Pete (Dave Franco) that turns into an endurance stand-off is wonderfully absurd, as is a sequence where Kelly wakes up and discovers she forgot to pump milk for the baby. Rose Byrne tears into her material with a comic zest that gives the movie a nice boost, organizing and executing a confrontation between two frat members with military precision, as well as playing the physical comedy of the milk sequence to the hilt. She even gets some pointed jabs at women's roles in films like these (again, possibly aimed at Apatow), which comes off more subtle than some of the film's other self-aware humor. Ike Barinholtz plays Mac and Kelly's sleazy friend Jimmy, and he steals at least one moment in every scene he's in (and perhaps the entire movie, with an incredible line reading that successfully sells one of the film's edgiest jokes). There's not much more to the "Robert De Niro party" glimpsed in the trailers, but the sight of Franco's squinty mug is a comedic gift that keeps on giving, and frat member Jerrod Carmichael has an extended, howl-inducing run with Hannibal Burress as a dim local cop. (Strangely, top-billed Christopher Mintz-Plasse is hardly present, his gags reduced more to "prop" humor than anything character-based.)

The core of the comic concept here, however, seems to rest on the casting of Zac Efron as Teddy, and he's a bit of a non-starter. There's a sense that he's supposed to get credit simply for being willing to be in the film and roll with whatever Stoller and company asked of him, but Teddy's barely a character. Threads about his extremely low IQ and the harsh reality of life after college stand out as strong hooks to hang his performance on, but neither idea really factors in outside of the scenes in which they're introduced. He may not give a bad performance, and it's nice to know he's willing to make jokes about his abs, but his participation has the depth of a "Saturday Night Live" sketch, and although he's good enough for Rogen, Byrne, and Franco to bounce material off of, his return volleys are uninspired. In the end, Neighbors is kind of like Efron: good looking, good-humored, but kind of empty.