To judge from the advertisements - and even some of the reviews - you'd be forgiven for assuming that Adventureland sees director Greg Mottola returning to the goofy, dirty comedy blended with sweet nostalgia that made Superbad a big ol' hit back in the summer of 2007. It is not. Oh my, no. No, no, no, no, it is certainly nostalgic and sweet, but goofy and comic, it very decidedly is not. Frankly, Adventureland is a great deal more melancholy than it is funny. In a good way.

Set in the summer of 1987, Adventureland is the story of what happens to young Pittsburgh resident James Brennan (Jesse Eisenberg) in the months separating his graduation from college and his entry to graduate school at Columbia. Looking forward to spending time in Europe, goofing off with his best friend from school, James's plans are interrupted horribly by his father's demotion at work, meaning that the belt has to be tightened fiercely around the Brennan household and for James to even be able to afford Columbia - forget about Europe - he's going to need to find a summer job. And for a young fella with no practical skills whatsoever (he was a comp-lit major), the best that Pittsburgh has to offer is the local run-down amusement park, Adventureland.

Adventureland isn't really a film about its story, though - everything I just recounted takes place in the first ten minutes, and the rest of the film could be easily synopsised in half the space - but about setting and characters. Based on Mottola's own recollections of his time spent working at the Adventureland park in New York, the screenplay (the first he has written since 1996's The Daytrippers) is thick with observation. Perhaps too much; many films have been set in the 1980s in the last three or four years, but I cannot name another so heavy with '80s-isms, from the clothing to the cars to the incredibly dense soundtrack. After a while, the production design seems to be as much of a character as any of the human beings drifting through the script. Is this a flaw? I genuinely don't know. It's clearly important to Mottola to capture a snapshot of his youth in all of its textures and nuances, even though I suppose that the events which happen to his alter-ego in the movie aren't actually rooted in solid history. And even though Adventureland wasn't shot in Mottola's old stomping grounds, it's still located firmly in that physical space known as "the author's memory"; the fervor with which Mottola recreates the setting of those memories - do we not all recall the spaces where things happened to us at least as strongly as the things themselves? - leaves the film occupying something of the same space as Marcel Proust's In Search of Lost Time, literature's finest example of a man recreating the tactility of his remembered places.

The narrative matter of Adventureland concerns one of the hoariest of all tropes: it's a coming-of-age story. James begins the film lost in his own head, a place full of inscrutable theories about art and humanity, virginal and socially incompetent; because of Adventureland and the people he meets there, he is awfully close to being a fully-functional adult by the end of the movie. Stories like this are beyond common, and always predicated on the fairly dubious idea that we all have that one time that made us who we are; but there's something about a good coming-of-age story that's, well, good, no matter how familiar or divorced from reality the ingredients may be. Adventureland is, for a few scattered reasons, not much more than good, but that's enough.

Chief among the characters who affect James over his summer is Em (Kristen Stewart), the pretty-but-not-inaccessibly-so girl who works with him on the Adventureland games team; usually her role is filled by a Manic Pixie Dream Girl, but Mottola is careful to write Em in such a way that even though she isn't remotely as round a figure as James is - her entire character is effectively rooted in "I hate my snobby stepmother" - there are hints at depths that make her seem more than just the girl who makes our male protagonist learn important life lessons. The other characters include Joel (Martin Starr), Jewish nihilist and intellectual who is apparently a couple of years older than James; Lisa P (Margarita Levieva), the hottest girl at the theme park, neither terribly self-obsessed nor intellectually curious; Bobby (Bill Hader) and Paulette (Kristen Wiig), the park's managers and by a significant margin the funniest element of the film - the comic relief in an ostensible comedy. Last and maybe the most important is Mike Connell (Ryan Reynolds), a married man who seems to be right on the verge of 30 if not just a touch older, the park's chief maintenance man who has an affair with a different girl every summer (it's Em this time around), and who makes himself feel better about the life he's wasting by impressing everybody with the probably apocryphal story of the one time he jammed with Lou Reed.

On paper, this is fantastic stuff, deeply sensitive and unnaturally perceptive. The film goes out of its way to avoid making villains (although the parents in the film are generally made of much thinner stock than everyone else) and suggesting very real divisions of gender, class, education and skill without letting any of them overwhelm the central issue: James figuring out what he wants from life, now that the security blanket of college has been cruelly pulled away from him.

It's in the execution that Adventureland manages to screw a couple of pooches. For starters, it's shockingly uncinematic. Not "bad" - nothing is out of focus, you never see equipment in the frame, shots don't linger on for five seconds too long as the actors just stand there. And movies like that exist, so it's not well to take it for granted when those problems don't show up. But there is almost never a time in the film when it feels like a particular camera set-up, or a dolly shot, or a cut at this frame instead of that frame serves any kind of purpose whatsoever. It is the most absolutely indifferently made film that I've seen in a very long time, as though the one and only reason that it was a movie and not a radio play was to show off the costumes and art direction. Other than that, Mottola and his crew seem wholly disengaged from any kind of cinematic vocabulary.

As for the cast, there are nice surprises and expected triumphs; take Martin Starr, one of the "Bunch of Guys" from Knocked Up, here given a much more prominent role and taking it all the way in. So deadpan that it stops being actively funny, his take on Joel is the most natural thing in the movie, and the character is revealed to be the smartest but also the most fatalistic in the film thanks mostly to his performance. The bigger and perhaps better surprise is Ryan Reynolds, an actor who I never gave up on because I never expected anything from him in the first place; it turns out that when you give him a smallish role that isn't romantic-comedic, he is a pretty much great actor, making what might well have become a thuggish villain nearly as sympathetic, and far more pathetic, than the hero. Meanwhile, the one-two punch of Hader and Wiig, though given far too little to do, showcases the finest comedy in the film, a combination of his gusty cartoon enthusiasm and her absurdly dry reactions.

The leads, though... it's hard to judge, since the film is about unformed young people. Kristen Stewart certainly lands that one: she's so anonymous and impersonal, it's incredibly easy to believe her in every moment as a young woman who is completely lost in her own life. It's a terrible performance (and yet, not even close to the worst performance that the star of Twilight and The Messengers has given us), but it's bad in a way that serves the film. And Eisenberg, kind of the same thing. He's playing an older version of the character he played in The Squid and the Whale, and I didn't much care for him then, either (8-years-younger Owen Kline in the same movie was much more successful, I thought). Again, it's the kind of role that needs a somewhat un-lived-in performance to work, but I got a wee bit antsy every time Eisenberg said anything or moved: he's so goddamned stiff! And he talks too fast. I look around and see that everyone is heaping all kinds of praise on him; de gustibus non est disputandum.

I simply can't regard Adventureland as a wholly successful movie: the key performances don't work much for me and I feel like watching a table reading of the script would be roughly as effective as actually watching the movie - the craft elements of the film are really that flaccid. But it's impeccably written, there's little doubt about that. Even if he didn't quite know what to do with it, Mottola still deserves credit for one of the loveliest pieces of nostalgia that I've seen in a good long time.