Tacky and intermittently entertaining is all"Piranha 3DD"sets out to be, and that is all this playfully graphic horror-comedy sequel accomplishes. It is a relative compliment to call the film a perfectly acceptable summertime air conditioner movie for those looking to zone out in a cool room for a spell.
The film centers on marine biology student Maddy (Danielle Panabaker), who plans to spend the summer working alongside her stepfather (David Koechner) running the family water park, which following her mother's passing he has refashioned into a more adult-themed attraction. (Best not to think on the chlorine bill.)
Her friends (Katrina Bowden, Meagan Tandy, Matt Bush) pitch in, as her ex-boyfriend (Chris Zylka) also hovers around. Then the super-sized prehistoric killer fish from the 2010 precursor "Piranha 3D" find their way to the park's illicit water supply — "underground lakes and rivers" is said often — and chaos, a lot of biting, bleeding and bare body parts ensue. David Hasselhoff also makes a cameo as himself.
"Piranha 3DD" becomes an inadvertent study in contrasts, as certain ideas work some of the time. The 3-D effects — lots of leaping fish — are at times jittery and unconvincing, yet other times provide a genuine added jolt. Its teasing jiggles are much more exciting than its straight-ahead nudity.