Earthbound is a mess, plain and simple, which is doubly disappointing given all the awesomely schlocky B-movie promise of the pre-credits sequence. We learn the tale of Mathius and Jace, the sole refugees of a distant planet called Zalaxon, which has been torn apart in a civil war. Mathius fled the planet with his son, who was due to be sacrificed by the enemy in order to win the war…somehow. Jace lives on as the “Last Son of Zalaxon” in exile. Presumably this is also a symbolic title, as his warring planet is still awaiting his return by way of a signal beacon visible through a wormhole that opens every few years between Zalaxon and Earth.

And you know what? All of that is just fine. This film takes an absurd space opera and spells it out via a dazzling series of colorful comic book panels, leaving the audience begging for more. But all of the delight and incoherence of this premise could have only succeeeded if this film had the slightest idea of what tone it was going for. If I’m to judge by Liam Bates’ oppressively cloying musical score, the film is trying to be a grown-up version of E.T., replacing the earnest and childlike alien relationship with that of a pair of desperately lovestruck adults. Joe, the 10-year-old boy formerly known as Jace, loses his father Bill (né Mathius) (David Morrissey) at the age of 10. Before dying [of unspecified causes], Bill lets his son in on his extraterrestrial origins, leaving behind a collection of retro-futuristic children’s toys and otherwise human-looking objects as evidence. But more on this collection later.

Fifteen years later, Joe (Rafe Spall), now working as a clerk in a comic shop, instantly falls for fellow sci-fi fan Maria (Jenn Murray) by way of an electronic wristband that instantly informs him of their 93% genetic compatibility (well past the 85% that he needs in order to knock up one of those easy Earth girls). While “you’re the only hope for my people” might have actually had some success as a pickup line, Joe wisely conceals his true identity when asking Maria out. But what we get instead are some of the most insipid attempts at romantic dialogue this side of Attack of the Clones, made even more obnoxious by the score’s various attempts to make me think I’d felt something for these star-crossed lovers. The two performances are individually decent, but weren’t remotely believable as romantic partners, with Murray’s earnest sadness and Spall’s unrelenting quirk making an incredibly poor match when sharing the screen.

This film had all the elements of a successful piece of sci-fi, but no earthly idea how to fit them all together. Among Joe’s gadgets was a holographic projection of his father – a device that served virtually no purpose beyond exposition and plot contrivance. This is neither Jor-El nor Obi-Wan. While there’s a chance of poignancy in the idea of Joe conversing endlessly with an affectless husk of his dead father, the various attempted emotional beats in this “relationship” utterly fail to land. When Joe is potentially forced to give up on seeing his projected father ever again, the dilemma inspired nothing more than a tepid yawn, and was over just as quickly. If Joe doesn’t care, why should I? And his choices don’t seem to matter much anyway. Each of Joe’s mundane-looking alien devices had to stop working at just the right moment to prevent anyone from believing his story, and start working again just in time to be useful or muddy the waters further. The film tries to delve into psychological thriller territory by forcing Joe to doubt the veracity of his tale, but given the clunkiness with which his doubts are established, it doesn’t remotely succeed. Apart from a hilariously dark performance by Stephen Hogan as the world’s worst psychiatrist, there is very little to redeem this act, and it attempts so many unsuccessful twists and reversals that it all becomes downright tedious.

But the final sequence very nearly saved it. Some vague spoilers will follow. By the time we reached the third villainous monologue, in which the baddie just can’t kill the hero without first talking his ear off about how thoroughly he has been beaten, I thought perhaps the film had found its footing again. The final sequence would feel right at home in a 50s sci-fi romp, and it was this loving and old-fashioned treatment of the genre that made me lament just how much of a missed opportunity this is. Earthbound is actually quite well made, and everything – from the production design and effects to the majority of the performances – seemed just adept enough that it all should have coalesced into something just a bit more watchable. But for a film that only has enough plot to fill perhaps a single decent episode of Doctor Who, the rest just feels like the disorganized cutting-room bits of a different project.

FilmWonk rating: 4 out of 10