A film about two annoying, self-absorbed thirtysomethings living in Los Angeles and struggling with the idea of mortality hardly sounds like the stuff of great cinema. Throw in the fact that the movie is narrated in part by an injured talking cat called Paw-Paw and the project sounds like one for the celluloid scrap heap.

Yet The Future, which deals with the impact Paw-Paw has on the couple after they agree to look after him, has been one of the cult hits of America's art-house scene this summer and its creator, Miranda July, has been hailed as one of the hottest names in independent cinema.

The praise heaped on The Future far outstrips its seemingly flimsy and self-consciously odd plot outline. "Beguiling, quietly funny and finally very sad in a way that sneaks up on you before becoming clear as the Los Angeles skies beneath which it's set," enthused Chris Vognar of the Dallas Morning News. Ann Hornaday at the Washington Post called it "radical" and "otherworldly". Not surprisingly, the movie was a huge success at the Sundance film festival.

Now July is basking in its success. After all, she wrote The Future, and she starred in it and she directed it. But July's current triumph is only the latest peak in an artistic career that has gained her plaudits as one of the most wide-ranging artists working in America today.

For not only is The Future her second successful film, but July is also an acclaimed performance artist and an award-winning short story writer. Yet throughout her work her trademark style is the same: a whimsical exploration of seemingly ordinary moments and emotions, fraught with a dark, unsettling undercurrent.

"She gets attention because she is individual and quirky. She takes small emotions, frustrations and humiliations and makes them into a much bigger thing," said Kristen Baumlier-Faber, a professor of digital arts at the Cleveland Institute of Art.

There is certainly little doubt that July, 37, is talented. Her previous film, Me and You and Everyone We Know, came out in 2005 and was an instant smash hit on the independent film circuit. Her work as a performance and video artist, performing in venues all around America, has long been a staple of the US avant garde.

One of her main works, a web project that lasted seven years called Learning to Love You More, has been acquired by the San Francisco Museum of Modern Art. Her writing, too, has been a hit. She has had fiction published in the New Yorker and in 2007 her collection of short stories, No One Belongs Here More Than You, won the Frank O'Connor International Short Story Award.

Yet in all her work her style is largely the same: she eschews traditional plots and narrative-driven stories to focus on emotion and feeling. "She is trying to show the inner life of characters. More mainstream work focuses on a story, but she has never done that," said Baumlier-Faber.

The Future fits that framework perfectly. Relationships break down, emotions fray and scenes of magical realism play out amid increasing confusion as to what is true and what is fantasy. At one stage the boyfriend character in the film asks the moon for advice and a voice responds to his pleas from above. However, rather than dispensing celestial wisdom, it simply says: "I don't know anything. I'm just a rock in the sky."

If some of this lyricism sounds familiar, it is because July is perfecting the various themes and emotions associated with other "whimsical" and "ironic" artists, working especially in film. They would include actors like Michael Cera and Zooey Deschanel, who are both wildly popular with the "hipsters" of fashionable neighbourhoods such as Williamsburg in New York, Silver Lake in Los Angeles, Portland in Oregon and Hoxton in London.

It also covers directors like Wes Anderson, whose stylised and surreal films include The Royal Tenenbaums and The Darjeeling Limited, and Noah Baumbach, whose The Squid and the Whale also focuses on family emotions and drama as its central theme.

July fits squarely into this model of left-field chic. She grew up in Berkeley, California, as Miranda Grossinger, the daughter of two writers (she adopted the name July after a character from a magazine she made at high school). Her hipster credentials are impeccable: she dropped out of college, moved to Portland to be a performance artist and now lives in Silver Lake with her indie director husband.

To their fans, the works of July, Anderson and Baumbach are whip-smart and intelligent. But to their critics they are indulgent and overly focused on the perceived problems of a literary, white middle class.

"I have always found her to be 1,000 per cent pretentious. It's masturbation, that's what it is," said Richard Laermer, pop culture expert and author of the book 2011: Trendspotting for the Next Decade. But that sort of criticism hardly does justice to the real vitriol that July can inspire in some cultural critics and artists. One detractor has even set up a blog entitled "I Hate Miranda July".

Indeed, extreme criticism of July isn't hard to find. "Her pretentious, cloying, stab-me-in-the-eye films are triumphs of cinematic torture," wrote blogger and writer Judy McGuire, before describing how she would like to beat July repeatedly with her shoe.

The criticism against July and others who create similar genres of art are nearly always rooted in the same arguments. Their work is all too often twee and overly self-conscious, the debate goes, with far too much attention paid to the sort of everyday issues that everyone encounters but can't afford to get worked up about because they have real problems – like mortgages, illness, jobs and the recession – to deal with.

Again, The Future fits the bill. The thin, unlikely plot has the central couple's lives stricken with chaos by the mere prospect of looking after a cat with a hurt foot. With a month to go before Paw-Paw arrives at their home, July's character and her partner set about desperately trying to achieve things as if they have been told they have only four weeks to live. The result is a catastrophic collapse of their lives.

Perhaps it is understandable, then, that July gets some critical mud flung at her. On the other hand it is hard to dispute that she is a genuine artist making a genuine statement, even if there are those who believe that her work can be dismissed as overly whimsical and loaded with hipster allusions.

After the success of her first film, July could easily have taken a more mainstream direction. Hollywood was knocking at her door. But instead The Future is an even more arty, experimental project marking a pronounced move further away from the sort of fare that dominates the world's multiplexes.

"That is obviously the way she wants it," said Caryn James, a film critic for Indiewire, a news blog that covers the independent film industry. James praised July for having a personal and original vision that flowed through her work, whether it be film, performance art or short stories. "It is a sign of that originality that she inspires such extreme reactions. Some people adore her and others just want to run the other way," said James.

It is unclear how much July cares about the criticism – or the adoration either. She has said that her next project in her artistic life is likely to be in one medium she has not yet tried: a novel.

"It seems like one of the last normal expected things that I haven't had the competence to try. But, who knows, maybe I don't? And I guess it's the fear that makes me do it," she told one interviewer recently.

Doubtless any book July does write will follow the same tried and tested formula of emotion over plot, and feeling over storyline. It is also likely to inspire the same mix of anger and adulation. But, in an age of reality TV and the relentless search for the lowest common denominator in so much of contemporary entertainment, that is perhaps no bad thing.