There have always been and will always be motion pictures about subcultures, but creating a feature about Manhattan bike messengers, with an emphatic message about how riding fixed-gear bicycles without brakes is the finest and noblest of pursuits, now that's tapping into an insulated community that matters to essentially no-one in the world. Perhaps surprisingly, this does not end up hurting Premium Rush, which sure as hell sounds like it ought to be the most insufferably indie, hipster thing on two wheels; except insofar as this is presumably what doomed the movie to a quick, merciless box-office death, which I guess must hurt a little.

It deserves a better fate than that. By no means is the film perfect - its imperfections, in fact, are singularly obvious, and not only would they have been easy to fix, it probably took more work to create them than correcting them would have taken - but it's an ideal August release (though it was first scheduled for January, after spending all of 2011 sitting on the shelf - two damning strikes), a rather straightforward genre riff that requires almost no intelligence to process, but which has been made by talented people who desired that it tick off as many of the boxes that come with its genre as possible. It is primarily fun, in a way that makes you feel glad rather than vaguely guilty that you went and had it.

And it's thrillingly brief: 91 minutes, over and done. That kind of concision sometimes seems to be a lost art in contemporary filmmaking, and do I sometimes give movies points just for not wasting too much of my life on a padded running time? I do. But it's a good thing for this kind of ultimately frivolous, fizzy entertainment: stick around for just long enough to be entertaining, and stop before bloat sets in. The same way you're supposed to eat candy, really, which is exactly what movies like this are: tasty, well-crafted, empty calories.

In point of fact, even at 91 minutes, Premium Rush suffers from some bloat, but it's not because the film takes to long, but that it makes some mistakes about what to do with its plot. Herein, we have a relative simple situation: legendary bike messenger Wilee (Joseph Gordon-Levitt) has been sent to A Prestigious Law School On The Upper West Side (for all that the film has a raging hard-on for New York geography, the word "Columbia" is conspicuous for its absence) to pick up an extremely sensitive envelope and deliver it to a woman in Chinatown. Before he's able to get off campus, he's approached by an extremely dubious man in a suit, claiming to be a university employee, but is in fact dirty NYPD cop Bobby Monday (Michael Shannon), who wants the envelope. Cue a chase up and down and all around Manhattan, complicated by Wilee's newly ex-girlfriend Vanessa (Dania Ramirez), romantic and professional rival Manny (WolΓ© Parks), a dogged bike cop (Christopher Pace), and several Chinese mobsters.

We don't really need more than that. The film itself knows this, for it takes great pains to demonstrate that Wilee's name is an affectation based on Wile E. Coyote, the star of several Looney Tunes shorts in which there is no trace of a plot beyond "one character wants to catch another, and fails" (and a dumb affectation it is, too: nobody seems to notice, within the movie, that the coyote in question is noted primarily for being crushed to a pulp by high-speed collisions with rocks, trucks, and the ground). All that Premium Rush requires, and certainly all that it promises, is a film-length chase between the clever, dextrous Wilee, and the increasingly frustrated, wholly inept Monday. This, at any rate, is the way that Gordon-Levitt and Shannon play their characters - Shannon in particular, whose spittle-flecked, miles-over-the-top bad guy turn that's just one "You meddling kids!" away from pure and unadulterated camp, is the film's strongest individual element and the basis for many of its best moments.

And, too be fair, a lot of the movie consists of absolutely nothing beyond that: high-profile blockbuster writer David Koepp, playing director this time around, understands what we're here for, and he and his stunt people have put together some extraordinarily fine bike chases, laced with gallows humor (Wilee has a knack for visualising the possible outcome for all moves he might make, which typically involve him being walloped by cars and thrown in the air like a dummy), and pepped up with ebullient scene transitions that imagine Manhattan as a model of the kind you might make for a school project; and most of it's practical stuntwork, too, a soppy love-letter to the days when filmmakers were limited by what was actually possible, and had to do what was actually possible in the most complex, convincing way to make their action movies (there's even an end-credits cookie with Gordon-Levitt, blood pouring from his arm, that's as much a "See? We actually did this!" gambit as a fun outtake). Sprawling, dumb fun, but good sprawling dumb fun, and exciting sprawling, dumb fun, and it is August, and thinking too much can be bad for you in times of elevated heat.

But, even though there really needs to be nothing at all beyond "Monday is bad, Wilee is good, now go" to set up the scenario, Koepp and co-writer John Kamps are extremely anxious to give their action a context and a frame, and that's when we get The Explanations. It's one thing to let us know why Monday is so damned anxious for that envelope, which is only fair - MacGuffins need to have some connection to the characters, or there are no stakes at all - though I do think that the writers tip their hand much, much too early for what amounts to be a bone-simple situation. Gambling debts. There, I said it in two words, and the film takes almost 10 minutes.

Because, instead of just having someone pop up and say, "gambling debts", Premium Rush rewinds its clock (almost every new scene is stamped with a graphic telling us the time, presumably to increase our sense of anxiety, though I did not find it did so), to earlier in the day, to show us exactly how Monday accrued those debts, and also throws flashbacks at a number of characters and situations that we don't absolutely need to see in such detail, giving thick backstories to characters who aren't important enough to deserve those backstories except that the backstories give them so damn much screentime. This does two things, both of them bad: it robs the film of its tight alliance to Wilee's perspective, thereby robbing the action of its inexplicable chaos and thus much of its fun; far worse, it slows the film down, and given how early the flashbacks start, and how many of them there are, that means that the film never quite builds up all that much momentum. Do we need to know about a young woman's travails with Chinese immigration? Not when it means less JGL onna fast bike, we sure as hell don't.

Ultimately, this is mostly at the level of annoyance: the movie is still heightened, quick-moving and entertaining, although it is possibly the least-entertaining version of itself because of all the chronological gamesmanship and narrative lard. The Premium Rush we get is fun and diverting, but there is a Premium Rush just one script revision way that is massively exciting and epically shallow in the best way, and I am somewhat disappointed that this isn't the one that was released. But still: Gordon-Levitt being cool, Shannon being apoplectic, and madly high-pitched music and editing driving the thing forward like a bat out of hell. One can complain, but not too loudly.