Filming a movie can be tough. Filming a movie in the Amazon rainforest, on a boat, while being threatened and occasionally attacked by a giant anaconda makes it feel as if it’s not worth the trouble. That’s the task faced with the character in Anaconda, who head to the rainforest in an attempt to document a native tribe that hasn’t been seen for years and years, despite new evidence saying that they probably are still around.

The reason, I assume, that nobody has seen them, is that the area is protected by a giant anaconda, who serves as one of two villains in our film. Of course, that’s why you’re going to go see a movie titled “Anaconda,” isn’t it? You want to see the titular creature hunt and then eat all of the less important characters, while the more important ones live until the end, only to either die or kill it. You pretty much know how it’s going to play out as soon as it begins, save for its exact conclusion. You’re here for the journey, to watch how a giant snake can kill people in increasingly creative ways, and to see how the filmmakers manage to recreate a 40-foot anaconda on-screen, and have it interact with people.

The answer to that last part, as far as anyone will be able to tell, is a mixture between CGI, animatronics, and possibly some close-ups of a real snake. It is mostly believable, even if there are some parts where the computer generated special effects stand out and are obvious. Despite this, it won’t take away from the film, and some of the CGI is actually quite impressive. The animatronics make if feel more real, though, and it’s nice to see practical effects being used whenever possible.

The cast: Jennifer Lopez plays the documentary’s director; Ice Cube is the cameraman and maybe her boyfriend (she has a second lover and I’m not sure if it was supposed to matter or even be a secret, as the film does nothing with that storyline); Owen Wilson is the sound guy; Eric Stoltz and Jonathan Hyde play roles that really don’t matter; Kari W├╝hrer is the second woman and nothing more; Vincent Castellanos is the ship’s captain; and Jon Voight shows up early on, having had his own boat break down and jumping ship to theirs. He captures snakes for a living and has a funny accent, so of course he’s to be trusted.

Voight is by far the most fun to watch out of these people. He’s hammy here, and seems to be having a lot of fun playing the slimy man you know little about. He knows his way around the river, and definitely comes in handy, but there’s a glint in his eye that tells you he’s not to be trusted. You don’t have any choice, though, and soon enough, you’ll find out exactly what he’s up to. It’s the only memorable performance in the film, and part of the only reason Anaconda is any fun.

I mentioned that the snake is one of two villains. I stick by that, but I’m not going to let you know who the second one is. You’ve probably already guessed it — correctly, I might add — but if you still have a hint of doubt, I’ll let you hold onto that for now. Most of these people are fodder for this giant snake at one point or another, usually after they’ve done something morally reprehensible.

Actually, that’s often what it seemed like in this film. If a character did something “wrong,” chances are he or she would be eaten soon afterward. Sometimes, this death would come later, but it would come. The anaconda is punishment for the sins of this person. Or, perhaps yet, this is just giving the film way too much credit. I still think it’s a valid point, and might make you look at Anaconda in a slightly different light.

Regardless of whether or not you think that theory is valid, there are still some creative kills and enough character banter and tension to make things interesting for the majority of its running time. While none of these characters are very well defined or developed — they’re mostly here to fight with each other and then get eaten — at least you can tell who is who and why they’re here in the first place. At least, that’s the case for most of them. For a couple, I wasn’t quite sure. And I was actually okay with that.

The only major obstacle stopping Anaconda from being completely worthwhile is that it doesn’t seem to have a middle gear. This is, reportedly, a horror film, so you expect some thrills, chills, and scares. The film will go from being completely safe to not at all in a matter of seconds, with no ability to build intensity. The payoffs are weaker as a result. It’s either not trying at all or going full-out. Giving it your all is fine and all, but it doesn’t make for the most engaging experience.

Still, the snakes look good, you can tell who each character is, the rainforest is wonderfully shot, and Jon Voight alone makes the trip worthwhile. It’s just never really all that scary or even thrilling. It has a few moments, but works much the same as Alien: There is a thing out there that will eventually kill everyone, and you’re just here along for the ride. When the fates of most of these characters are this inevitable, and the filmmakers don’t ever do anything to make the payoffs worth it, most of what you’re here to see won’t work properly.