96 min. | PG-13

This dark thriller has a nifty premise: an interactive online game in which its participants accept dangerous challenges at the bidding of the anonymous voyeur-participants posing them. (The prize money for live-streaming the stunts is an added incentive for a cash-strapped player.) It’s a cyberspace variation of “Truth or Dare,” without the option of answering a squirmy question to avoid a provocative dare.

Initially, the film is slow out of the gate in establishing the interpersonal dynamics of a group of Staten Island high school seniors. But the movie really starts to buzz when shy, insecure Vee (Emma Roberts) accepts the watchers’ challenge to kiss a stranger in public (Dave Franco) for $100. The experience is intoxicating for both of them—and you—as the risks crazily escalate (like driving a motorcycle blindfolded at a high speed) with each round. Until its heady but hard-to-swallow resolution, this heart-thumper lives up to its name.

The idea of anyone becoming immersed, either as a player or watcher, in a life-threatening techno-diversion may sound far-fetched. However, Nerve will jangle with a resonating and perhaps unpleasant truth for the internet-savvy crowd. It taps into the plugged-in zeitgeist in a big way. Today, young people use cell phones to spot virtual Pokémons while driving. It’s a brave new world that Aldous Huxley never imagined.

The finale of Nerve plays like a gladiator fight to the death in Rome’s Colosseum, with the not-so-passive watchers voting their thumbs up or thumbs down with the swipe of a screen. There are some real thrills up to this point, so the film’s ambitious but untidy conclusion disappoints.

Don’t try to sort it out afterward; Your brain will only freeze up. It’s best to remember the preceding wild ride made all the more pleasurable by the winning turns by the leads. Roberts’ and Franco’s first-rate performances in this better-than-average genre flick exude something called charisma. After this film, the two of them may graduate from watchers to players.