Ever since the dawn of the modern blockbuster era with the arrival of Jaws in 1975, the imminent release of a new high-profile movie seems to have become as much a matter of how much cash it's likely to rake in as how enjoyable it is to watch. Most of the advance blogosphere buzz surrounding John Carter, Andrew Stanton's forthcoming adaptation of Edgar Rice Burroughs's John Carter of Mars novels, has centred on its ballooning budget ($250m or more) and poor "tracking" results. Forgive me if I couldn't care less how much Disney has spent on the film, or whether Jethro Richardson of Florida and his two teenage sons are looking forward to seeing it: I caught the film a couple of weeks back and it is a joyously barmy boys-own space romp with a hundred times more heart than a film like The Phantom Menace, which it is being unflatteringly compared to.

John Carter may well end up being the Heaven's Gate of fanboy film-making, but Stanton's movie is no Adventures of Pluto Nash or Speed Racer. The Oscar-winning director of Wall-E and Finding Nemo simply has too much storytelling nous to let his film sink under the weight of expectation or cost, and it displays considerable earthy humanity for a movie with more than its fair share of talking CGI characters. By way of example, one may have to adjust one's eyes to get used to the preposterous sight of Willem Dafoe in motion capture as 15-foot tall extra-terrestrial Tars Tarkas. But it's hard not to laugh when a communication breakdown leads to the latter referring to a clearly irritated Carter as "Virginia" for the entire opening act (this of course being the name of the Earthling's home state rather than his name). The excellent chemistry between Taylor Kitsch as Carter, and Lynn Collins as Princess Leia-like native Dejah Thoris, and some fine supporting performances from the mostly British cast (Mark Strong, Dominic West, James Purefoy) also help dissolve any lingering concerns over the ridiculous nature of the setup.

If Stanton has made a mistake, it was in his decision to allow studio bigwigs to lop the Mars suffix from the film's title, a move apparently made in the wake of 2011 box office disaster Mars Needs Moms. Never mind that filmgoers turned out in their billions to see James Cameron's Avatar in 2009; clearly we all hate movies set on other planets.

Any attempt to obscure the nature of John Carter was doomed to failure from the start. The film's storyline sees jaded confederate civil-war veteran Carter (Kitsch) miraculously transported to Mars, where he encounters four-armed green aliens known as Tharks, sexy ETs who look pretty much like you and me, and weird aliens such as giant, blind, four-armed white apes, or huge but zippy canines. The creator of Superman, Jerry Siegel, decided that an extra-terrestrial arriving on Earth might benefit from special powers due to the difference in conditions from those of his home planet. Long before that, Burroughs had decided that an Earthman on Mars might appear superhuman to the natives, who call their world Barsoom. Neither author was presumably thinking strictly along scientific lines when positing his theory, but who cares when it gives Stanton the opportunity to throw Carter around like a ninja marionette, battling villainous martians like a balletic whirling dervish in a loin cloth?

It would be an awful shame to see John Carter fail to find an audience, of course. Two years ago Disney put out a deeply disappointing Tron sequel, which nevertheless made money, and Warner Bros are apparently threatening a sequel to Green Lantern, 2011's poorest comic-book movie. Stanton's film is probably the finest work of its (admittedly nutty) kind since Avatar, and is considerably less formulaic than that much-derided movie. The film leaves the door open for sequels without damaging its credibility as a standalone creation, and with more than a dozen books to draw on, this is a series that could potentially run and run. I should also mention the clever framing device which allows Burroughs himself to appear as a supporting character: its genius becomes apparent in the final scene, which is one of the most outlandishly brilliant things I've seen in mainstream film-making all year.

John Carter is the kind of movie no studio bigwig in their right mind ought ever to have greenlit: a space fantasy based on a genre – "planetary romance" – that hasn't been popular for well over half a century, populated by bizarre creatures from the mind of a writer apparently endowed with the ungrounded imagination of a small child. This is exactly why you should be checking it out. The film is out next weekend and I've posted the final trailer above. What a glorious enterprise Disney have wasted all their money on. God bless Hollywood!