SAFETY NOT GUARANTEED (R) It's admirable when a filmmaker deviates from the ongoing fashion of relentless cynicism. Replacing it with forced naiveté, however, isn't making anything better.

Clever indie comedy/drama Safety Not Guaranteed, the feature debut of director Colin Trevorrow, tries to have it both ways. At first, the movie trades on the sort of "edgy" hipness it ultimately decries. Aubrey Plaza, who plays the brutally sarcastic yet affectless dead-eyed intern April Ludgate on the sitcom "Parks and Recreation," plays the exact same character here, although now her name is Darius and she's an intern at a Seattle magazine. Jake Johnson, from the indie romantic comedy Paper Heart and sitcom "New Girl," plays piggish journalist Jeff, who gets approval to write an article about the person who submitted a mysterious classified ad requesting help to go back in time for a secret mission. Jeff, Darius and another intern, nerdy Indian student Arnau (Karan Soi), head to a small Washington coastal town to track their subject down. When they do find their man (which is surprisingly uneventful), a painfully earnest, mentally unbalanced cashier named Kenneth (Mark Duplass), world-weary Darius and Jeff are forced to reevaluate their prejudices and pessimism, ultimately opening their shriveled dark hearts to the fuzziness of the New Sincerity.

Written by Derek Connolly, Safety Not Guaranteed was a big sensation at this year's Sundance Film Festival. The premise is tight (it's based on a real ad that became an Internet meme a few years ago), the blossoming romance between Darius and Kenneth is at times sweet, and the mix of lo-fi science-fiction elements with humor is refreshing. When the movie works, it's funny and engaging. But when it stumbles, it crashes hard. At only 86 minutes, it feels overlong and disjointed. Connolly and Trevorrow take that airtight scenario and inflate it with a ridiculous subplot involving Jeff's attempts to hook up with an old girlfriend (the excellent Jenica Bergere). The big problem is that Jeff is easily the most annoying character in the movie. There's no reason to care for his plight. The other major problem is that Kenneth obviously has severe mental problems. But the filmmakers shove any concern about that aside so that the characters (and the viewers) can revel in cheesy '80s-era Spielbergian nostalgia without any of that nasty old cynicism getting in the way. The real cynicism is that so many are buying into it.