Ray Bradbury first published the short story A Sound of Thunder in 1952. It’s a brief, economical piece of storytelling with a fantastic idea and the kind of voluptuous prose that made Bradbury famous. The idea? When time travel is invented sometime around 2055, people with too much time on their hands take the opportunity to hunt the ultimate predators: dinosaurs.

Unlike the makers of the 2005 film adaptation of the same name, Bradbury realized his story was all about the idea, not the characters or even, necessarily, the world he created. Of the five men who journey back to the cretaceous period to take down a Tyrannosaurus Rex, only two receive any meaningful characterization: the safari leader, Travis, who serves to explain the rules and pitfalls of time travel, and Eckels, our unfortunate hero.

Eckels is a dolt who overestimates the size of his cojones, and Travis is too smart to be leading such a ridiculous indulgence of the whims of the rich. That’s it. That’s all we know about these characters, because the ideas in the story are too absorbing to cut away from.

Most of those ideas have to do with how the time travelers endeavor to leave no trace on the past. A levitating path keeps the group off the ground, as one wrong step onto a blade of grass could — if the company’s prevailing theory is correct — create a cascade of changes over time that would make the future unrecognizable. For similar reasons, any bullets expended must be retrieved, and the participants must wear gear that keeps human bacteria from entering the ancient atmosphere. The only dinosaurs hunted are those that are about to die by natural means anyway.

Then there is the T. Rex itself, which is depicted as a monstrous creature covered in wriggling parasites and stinking of raw meat. It’s no wonder Eckels loses his nerve, inadvertently falls off the path and crushes a butterfly, causing the mother of all domino effects that ultimately leads to the rise of anti-intellectualism and a fascist president in the future.

Now that we’ve covered the original story, let’s talk about the film adaptation that gets just about everything wrong in the funniest ways possible.

The 4400-word story doesn’t offer nearly enough character or plot elements to sustain a feature-length film, so the first major addition comes right off the bat, when we learn that Charles Hatton (Ben Kingsley, in a performance that can only be described as goofy), the CEO of Time Safari, is a money-grubbing narcissist who has exploited time travel for its financial potential.

Hatton has a government inspector in his pocket and a safari leader, Travis, who is willing to debase himself in order to advance his animal cloning research (in this version, all animals aside from humans are apparently extinct due to some kind of virus. If you want more of an explanation than that, too bad, the movie doesn’t care).

The time machine and levitating path seem cut-and-pasted right out of Stargate, but so far, Hatton is the only outright silly element of the film. That soon changes when Travis leads a pair of idiots back in time to hunt an Allosaurus and we realize that after Ben Kingsley’s salary, the film’s budget probably didn’t have a lot of breathing room.

Created more than a decade after the stunning majesty of Jurassic Park, the Allosaurus in A Sound of Thunder looks like something out of the Tron era. This is the only dinosaur represented in the film, as Time Safari apparently brings all their clients back to hunt the same dinosaur at the same point in time. Why aren’t all these safari groups running into each other? Too bad, the movie doesn’t care.

A bit later in the film, Travis returns to the Allosaurus with a new group of ding dongs, and when something goes wrong, the scene devolves into an unintentionally hilarious game of Benny Hill-style tag with a supposedly fearsome predator. The scene defies description, but suffice it to say that if you were to replace the Allosaurus with Barney, nothing would appear out of place.

We’re off the rails now, but there’s a long way to fall before we hit the bottom. As in the short story, someone steps on a butterfly, but rather than causing the subtle-yet-horrifying changes that Bradbury described, Travis returns to a world that experiences progressively more ridiculous transformations in a series of “time waves” that hit the planet like some kind of energy tsunami, causing the growth of supernatural vegetation and — you guessed it — reptilian baboon bats.

Why do these changes only affect the present rather than altering the entire timeline? What, exactly, is a time wave and why do the characters never ask this question? Why do two characters jump out of the window of a skyscraper to avoid an explosion, land in the vines of a tree that breaks their fall, then stand up and ask, “When did this tree get here?”

Too bad. The movie doesn’t care.

From here on out, the film is comedy gold. I amused myself (and annoyed my wife) by muttering “classic time wave” or “yup, that’s a textbook time wave” any time a new round of changes swept through the city. Your mileage will vary, but this was still funny by the time we got to the pterodactyl rat bats, the giant angler fish snake and the amphibious alien person.

It’s also worth mentioning that entire city, from the beginning of the film to the end, and from the cars on the street to the exteriors of the buildings, is a CGI creation. Scenes are frequently filmed as if to highlight the computer effects, which feature such innovations as backgrounds that move at different speeds than the characters in the foreground and vehicles so haphazardly placed that, at times, it appears characters are looking through them at something that should not be visible.

But one should not make the mistake of thinking that this film would be a masterpiece if not for the poor CGI. After all, I still have questions, such as:

Why, if what happened when the safari went awry is such a mystery, do the Time Safari employees wait for at least half the film to review video footage of the event that they have had the whole time?

Why does Travis claim that his safaris go to the Cretaceous period when the Allosaurus lived 50 million years earlier, during the Late Jurassic period?

And in regards to the ending, to paraphrase the immortal words of George Costanza: does coffee mean sex?

If you haven’t seen A Sound of Thunder, now is the time to give this unintentional comedy a watch.