The so called 'best of the Jaws ripoffs' seems sort of like damning praise when you consider how many of those must have existed in the late 1970s. Fortunately this quote is attributed to Steven Spielberg, and he was talking about a film from Joe Dante, someone who he'd later work with on several entertaining projects. He even stopped Universal interfering with the release which was close to their official Jaws ripoff, it's own sequel. It seems like an idea that should be boring, stupid slog - the killer fish movie. The premise itself sets off all kind of alarm bells - the search for two missing hikers accidentally releases the threat from ... a military research facility. But like anything, with the right amount of effort and a tone that works it can be made into something watchable.
The riffs on the original shark blockbuster are easy to spot, and they're mostly in the form of the busy public event being monitored by people who want to make a profit instead of safeguard lives. Dick Miller plays the summer park owner in this case who goes so far as to tell the press to be careful of incoming prank calls. You can trust him, he's a Texan... he says in his usual New York accent. He's not the only Dante regular even in this early directorial effort, and Kevin McCarthy plays the military researcher who created the deadly strain. For use in Vietnam no less. These kind of actors are what make a lot of this work. The best character is the stiff authoritarian summer camp leader played by Paul Bartel, who upsets the young kids so much they put his photo on a dartboard right where he can find it.
In terms of a structure the plot is pretty simple. The fish get out in the mountains and travel downstream, first eating a few locals, then the holiday makers, then they'll breed in the sea and reach unstoppable numbers. Of course they have to get a few reality checks out of the way first. These are mutant killer fish, bred for cold waters. They can even live in salt and fresh water after years of experimentation from which only the strongest survived. It's really hokey but I like that the explanation is included. The best tension building moments come from the river plot device, as they race first to block a dam and then to stop the swimmers becoming piranha chow. There's a great moment as the main characters find their raft is coming apart and they have to escape at the last minute. A small tourist boat has clear passenger limit painted on the side, so you know what will happen later. Simple setup, effective execution.
Of course plenty of people do get eaten, whether it's because of dangling legs while fishing or more absurd moments like crashing speed boats. The military colonel trying to cover up the incident is also a share holder in the theme park, and of course he gets his dues later on. While it's referred to as a parody these sort of small details are the kind of thing that make it fit that bill. The creature effects are about what you'd expect. They're used without too many of the strings being shown so it never becomes too cheap looking... though the same shots of fish going past the camera are recycled far too many times. There are some really weird and interesting creatures in the first act made by stop motion master Phil Tippet which stand out, both in terms of quality and their random nature. I get the mutation angle needed to be highlighted but this goes the extra mile for such a brief scene.
If there's a downside here it's that gets a little boring too early. The two leads are passable but not charismatic enough, and their efforts to save the day are halted quite frequently which effects the pacing. Just show the river map already, we know what's coming. It's also a problem that once the blood starts spurting there's nothing left to show and the novelty runs out fast. We already know who will die after all, and it's not going to be the little kids having a racing competition. Some parts are a little mean spirited as you'd expect, but it was never going to be that dark. The bizarre feeding sound effects are dumb the first time, and by the end they're just dull. All the splashing and biting sort of blurs together after a while. The final underwater sequence that fixes the whole situation is fun at least, again it's because of the simple plan being laid out ahead. It's no classic, but you know that just by looking... it's a killer fish movie. But it's better than it should be.