Ridley Scott’s Prometheus has an early shot which undeniably quotes 2001: A Space Odyssey, a beautiful image of a planet ringed with light. There’s some more striking imagery, of an unidentified landscape. A humanoid being removes his cloak and ingests some form of liquid which quickly begins killing him. He sacrificially gives himself to the river, where he falls apart piece by piece, his body possibly giving birth to life as we know it. That’s a provocative beginning for a big-budget science fiction film, one that clearly announces its intentions to be a thoughtful exploration of the creation and destruction of life. As they say, the road to hell is paved with good intentions.

After the cryptic prologue, things get off to a very good start. The crew of the good ship Prometheus–which looks like a jumbo Serenity, but maybe that’s just me–is awakened from cryogenic sleep after two years by the android David (Michael Fassbender). Scientists Elizabeth Shaw (Noomi Rapace) and Charlie Holloway (Logan Marshall-Green) have discovered cave paintings from around the world, all of which depict images of a figure gesturing toward the same star pattern. They’ve followed that pattern all the way out to the middle of space, hoping to find the meaning of life, the universe, and everything. There are some big ideas at play here, and in the early going, there are conversations about whether the existence of supposed humanity-creating beings (Engineers, they’re called) negates or supports the existence of God. Holloway posits that because they now know the Engineers exist, the cross Shaw wears around her neck is meaningless. Shaw, with a wink in her eye, then asks where the Engineers came from.

This is all tantalizing stuff, the kind of heady sci-fi that doesn’t make its way to the big screen as often as I would like. One of science fiction’s primary responsibilities is to step back and ask, What does it mean to be human? Prometheus offers an ambiguous response in the form of David. As the others sleep, David learns every language known to man and patterns himself after Peter O’Toole in Lawrence of Arabia. There’s a seemingly innocent calculation to his every action that is equal parts creepy and endearing. He’s only a robot, after all, and can only do what his programming requires of him. He does not feel emotion because he was not designed that way. And yet David exhibits some behavior which makes you question whether or not he has a will of his own. I don’t want to push the comparison too much, but I feel like the movie invites it: David is basically a walking HAL-9000. Michael Fassbender is terrific in the role, continuing a run of godly performances in everything from X-Men: First Class to Shame.

The crew explores a cave they think might be occupied by the Engineers. These scenes are full of eerie wonder. Behind every corner could be a life-altering discovery, and once they discover a headless alien corpse, “life-altering” might not be such a positive. Up until they leave the cave, the film has been smart, contemplative, and thrilling, basically everything you could want from sci-fi. The build-up to the film’s second half is so effective that your heart sinks when you realize–and I groan while writing this, because I feel like variations of this same thing have had to be said about almost every mainstream genre picture–that it’s going to devolve into your typical action-horror nonsense. Some of these scenes are exciting, but there’s also a lot of sketchy behavior from the characters. Rapace is a convincing lead, and the crew is filled out by remarkable actors like Charlize Theron and Idris Elba, but when shit starts going down, it becomes all too apparent that Scott has spent so much time creating a wonderful atmosphere that he’s failed to create characters whose gruesome deaths you would actually care about.

Scott and screenwriters Jon Spaihts and Damon Lindelof fail to really explore any of their big questions. I don’t need or want boring answers, which the film wisely doesn’t give, but I would like some follow-up or resolution, which the film also lacks. I can’t imagine who thought it would be a good idea to blatantly raise questions about the meaning of existence and the potential discovery of God-like beings, only to bring everything to a close with hack ‘n slash action and vagina squid monsters. Much hand-wringing was done before the film’s release as to whether or not it was a prequel to Scott’s Alien, which remains his masterpiece. It undoubtedly is. The planet the crew visits is LV-223, compared to LV-426 in Alien; the Weyland Corporation, not yet Weyland-Yutani, has a major role; obviously, there’s an android; and some other clues I won’t spoil.

I’m not sure what to make of the Alien connections, though. Scott has stated that he didn’t want Prometheus to be beholden to the Alien story, and he’s succeeded on that front. It’s got ideas and Engineers all its own. I’m fine with setting a different story in the same world, and maybe the connections will make more sense if Scott gets to make his hoped-for trilogy, but right now it feels like borrowing the familiar trappings of a beloved, tried-and-true franchise as a crutch. The film could stand on its own, but because it’s kind of sort of an Alien movie, it doesn’t have to. And if it is an Alien movie, it brings to the table some traditionally loaded sexual metaphors, lent weight by the film’s questions of birth and creation. There’s a squicky operation late in the game which contributes to the whole life-giving deal, but it doesn’t particularly seem to mean anything to anyone in the film. Also, see again: vagina squid monsters.

Co-writer Lindelof is best known as one of the showrunners behind the TV series Lost. Lost was another ginormous sci-fi parable that asked questions of life, death, creation, and destruction. It also gave viewers general “What does it all mean?!” paroxysms. Many fans were disappointed by the answers Lost ultimately gave or chose to provide, but I wasn’t one of them. Like Prometheus, there’s a lot in Lost that was left ambiguous and open to interpretation, sure to provide fodder for its rabid cult for at least the next couple decades. The key difference, and one I hoped Lindelof would be able to make here, is that Lost explored its questions and ideas through genuine human stories. Even when the show threatened to tip over into silliness, it was able to seem kind of profound. Prometheus lacks any such feeling. It sets up some rich themes, throws in some one-note characters to deal with them, then unimaginatively dispatches them one by one. It’s not 2001, it’s not Lost, it’s not Alien, it’s not any of the pop culture touchstones it knowingly invokes. It’s barely even its own thing. It’s just another botched summer tentpole.