Ugh. This is what I'm sure many of us feared Aja's Piranha would be. Just total amateur hour hackwork, cheap, lazy and witless. And, man oh man, does it feature a downgrade from the insane Saving Private Ryan D-Day-esque close of the first film. This one amounts to a couple dozen blood-covered extras splashing about in a pretty empty pool pretending to be eaten by piranhas that the studio was too cheap to actually put on screen. Embarrassing straight-to-DVD-quality shit.
There are a couple amusing gore moments, although they don't really involve piranhas. And the good one that does, makes no fucking sense. At all. It feels like an idea Gulager had for a while and just decided to shoe-horn in here.
As for nudity, I'd argue there's probably a bit more than the first. But nothing to match Kelly Brook and Riley Steele's underwater duet. Mostly just clumsy shots of naked extras thrown in sporadically. No actual characters get naked.
The young cast is pretty uniformly terrible. And there are two dudes that look identical to one another, and both play nerds with girl problems. Kind of confusing. As for the celeb cameos, Lloyd repeats his previous performance for too long, Busey is wasted, and Hasselhoff runs rampant to really unfunny effect. God, if I never see another Baywatch parody I'll die happy. Rhames is at least amusing, although I don't understand why he'd be hanging out with Paul Sheer's porn filmmaker dude...
I dunno, if you, like I, can find even slight joy in even the shittiest killer fish movies, this one won't bore you. But it's completely and utterly disposable, and a wild fall from the last Piranha flick.