Let’s get this out of the way: Ridley Scott’s Prometheus looks spectacular. It starts like gangbusters, establishing its own stately pace and sense of wonder.

And then the problems begin, resulting in an experience that is mixed, at best, and severely muffled, at worst.

To put things into perspective, it’s good to remember that Alien arrived in the post-Star Wars, post Close Encounters of the Third world of May 1979. Scott, who’d been directing television commercials before making his feature debut with the stylish but little-seen The Duellists, was an unknown. The cast featured no big stars. Advance buzz had developed, however, due to the devastatingly effective TV ads and the great tag line: “In space no one can hear you scream.” The film delivered, fusing the premise of a thriller with the atmosphere of a horror picture in a science-fiction setting designed by mad graphic artists.

The sequels that eventually followed wisely endeavored to blaze their own trail. James Cameron’s Aliens, for example, combined a monster movie aesthetic with a war-movie mentality and attached it to the raw physicality of an action movie coupled with the warm emotional appeal of mother-daughter bonding.

For Prometheus, Scott and co-writers Jon Spaihts and Damon Lindelof have spun a tale that is more purely “science fiction” than Alien, which at its roots was a genre picture. Prometheus aims to deal with the big questions of life: Who created man? Where did life originate?

The main mission of the movie centers around archeologists Elizabeth Shaw (Noomi Rapace) and Charlie Holloway (Logan Marshall-Green), who have discovered evidence that indicates aliens visited Earth in the distant past and created mankind — and they think they know where the aliens came from.

Funded by aged industrialist Peter Weyland (Guy Pearce), the years-long mission lands on a distant planet and a team sets off to explore. The key players are Weyland’s robotic “son” David (Michael Fassbender), ship’s captain Janek (Idris Elba), company executive Meredith Vickers (Charlize Theron), while sacrificial lambs are played by Rafe Spall, Kate Dickie, and others.

The early scenes are magnificently realized, immersing the viewer in a fully detailed future world. The “Prometheus” is a sparkling new ship with sparkling new technology, as opposed to the aged hulk that was the “Nostromo” in Alien. The visuals are compelling to watch, and the tweaks on characters and situations made familiar from the original film are enjoyably clever.

After a certain point, however, the big ideas are pushed to the back burner and the thriller component of the picture takes hold, and it’s in this section that the changes start to ring false, and the inconsistent logic and head-shakingly silly character behavior takes a toll on the suspension of disbelief. And then the third act shoots off in yet another direction, with a resultant change-up in the tone and pace, and it begins to feel like a huge mess.

The ambition is admirable, but Prometheus can’t shake off the overly-schematic nature of its narrative, which is nearly unavoidable for a prequel. After all, we know how Alien begins.

Prometheus makes a good-faith effort to create an entirely new experience, but ultimately it’s too reliant on re-using plot twists and narrative beats from Alien to stand on its own. Still, the parts of the film that work are better than most wide releases in their entirety this year, which means Prometheus is the must-see movie of the weekend for adults.

Prometheus opens throughout the Metroplex on Friday, June 8.