This flagrantly weird account of a 1970s Australian girl's 15th birthday is decidedly not for everybody. What starts out as a cutesy, Wes Anderson-ish look at high school life (complete with the 4:3 screen ratio Anderson employed in The Grand Budapest Hotel) soon descends into a wild David Lynch-inspired nightmare – though to reveal that this lengthy, latter section of the film is "only a dream" is hardly a spoiler. The title, in fact, alludes to it.
In short, you will either find Girl Asleep a thoroughly original fantasia of teenage girl angst, or an overly quirky bit of nonsense.
As for me, I liked it – though not strongly. What saves the film is its acting ensemble. Real-live teenager Bethany Whitmore charms as Greta, the shy new girl at school whose social awkwardness belies a treasure trove of fierce emotions, which all come to a boil during the birthday party that she doesn't want. The supporting players are perfectly cast, and the late '70s production design and costumes are awesomely on-point.
Myers' mise en scene, however, is hit and miss. The film's surrealist whimsy is laced with a hefty dose of what I can only call "Aussie camp", the sort of goofy over-the-topness found in Oz films like Muriel's Wedding and Strictly Ballroom. Sometimes it works, sometimes it doesn't. (Girl Asleep was actually adapted from a stage play; the Adelaide-based theater company behind the play also produced the film, with playwright/screenwriter Matthew Whittet playing Greta's father.)
See this film at your own risk. You might get a lot out of it, or it might only confound and irritate you. In any event, Richard Ayoade's 2010 British feature Submarine already covered much of the same ground, except far more successfully. If you haven't seen that one yet, do so immediately.