Metacritic reviews

The special effects are awful (the piranhas are obviously hand puppets) and the script worse.

Sound and image are consistently bad, and Piranha II is the first film in my experience to give screen credit (in opening and closing titles) to a man in charge of "special effects and prosthetics." It can't be an easy way to make a living.

It plays a lot like a Porky's holiday comedy for the first half, and then the seagoing killer fish learn to fly and big rubber toothy things terrorise the survivors.

A copy rather than a sequel, this has none of the intelligence, wit or tempo that graced the first swarm of hungry fish.

This is a routine monster film, unrelated to Joe Dante’s 1978 Piranha. Idiotic premise has US government genetic engineering experiments creating a deadly form of grunions (hinted at being used in the Vietnam war).