One of the problems with letting adolescent boys make movies is that adolescent boys are notoriously bad at knowing when a joke has run its course. The 15-year-olds* who made "Piranha," a 3-D boobs-and-blood explosion from two summers ago, got some mileage out of unapologetically gratuitous nudity and graphic violence, simultaneously delivering what the young male audience wanted while making fun of them for wanting it. But the sequel, made by a different set of 15-year-olds*, just does more of the same, only without any verve or novelty.
It's called "Piranha 3DD," and yes, they obviously came up with the title before they came up with anything else. The setting this time is an Arizona water park adjacent to a lake that may (spoiler alert) have mobs of prehistoric piranha living in it, and those fish may (spoiler alert) make their way into the pools and water slides. The owner, a sleazeball named Chet (played by excellent sleazeball David Koechner), is unconcerned about public safety, leaving his stepdaughter, Maddy (Danielle Panabaker), to be the heroine.
That's pretty much it, plot-wise, until the massacre begins. The slim running time (it's 70 minutes when the closing credits start rolling) is padded out with standard vignettes: some horny teens fool around in the water and die; Maddy has a douchey boyfriend (Chris Zylka) while her nice-guy platonic friend (Matt Bush) pines for her; celebrity guest stars get eaten; Christopher Lloyd, the dotty ichthyologist from the first film, shows up again to warn of doom; and so forth. Most of this is half-hearted at best, with 15-year-old* director John Gulager (of the "Feast" series) and his 15-year-old* writers seldom bothering to attempt wit or suspense.
The movie comes to life briefly when David Hasselhoff shows up as himself, doing duties as a "celebrity lifeguard" on the water park's opening day. Hasselhoff has reached the point in his career where he exists almost entirely as a self-aware parody, but as self-aware parodies go, he's pretty good. Also worthwhile is the return of Ving Rhames as the indestructible cop whose legs got eaten off in the first movie, now visiting the water park for a safe, non-traumatic aquatic vacation. ("I'm not afraid of some punkass water!" he declares.)
As you'd expect from a film made by 15-year-old boys, "Piranha 3DD" is brimming with lithe, naked women, yet is terrified of actual sex. Every sexual encounter in the movie ends in death, and the women are never naked during it. A man's penis gets bitten off by a piranha that somehow found its way into a hot virgin's hoo-ha: There must be a dozen Freudian symbols in that sentence alone. I wonder if the filmmakers realize how telling it all is.
Yet even as dumb trash the film can't quite succeed. It's not outrageous enough to warrant a you-gotta-see-this-to-believe-it screening, and the gore is nothing that gore fans haven't seen a hundred times before. Even by the absurdly low standards set by its predecessor, it's a disappointment. Maybe it's time to bring some grown-ups in.