Pierrot le Fou is definitely a French film. It's definitely from the sixties. Not what teenagers and politicians think of as the sixties. The actual period, when women's hairstyles looked especially wiggy.
And it's unmistakably the work of Jean-Luc Godard, who was at his peak during that decade. So he embraces the silliness and loads it with a lot of his own baggage. It holds up encouragingly well.
The plot is simple, allowing for a lot of sidetrips. Ferdinand (Jean-Paul Belmondo) used to work in TV, but he was fired. His wife, a beautiful woman with whom he has no connection of any kind, forces him to stay on the gladhanding and parties circuit. After one particularly vapid party - guests speak entirely in advertising blurbs - he sees that his babysitter for the night has been Marianne (Anna Karina, Mrs Godard at the time), and old girlfriend of his. So he runs off with her, leading a carefree life of robberies and the occasional murder with her that turns out not to be so carefree
If you find it difficult to take this story seriously, rest assured that Godard finds it impossible. Nor does he make much of an effort to sell it on a visual level. The killings consist mostly of men falling over when you hit them, sometimes with a little red paint on their faces.
This attitude toward realism - toggling between lackadaisical and outright hostile - frees him to concentrate on things he does find interesting. For a few scenes the film becomes a musical, one served well by Karina's singing voice. There are also elliptical philosophical debates, and a playlet about Vietnam that Karina plays in yellowface. Like, lemon yellow.
While American directors like Brian Depalma, Martin Scorsese, and Quentin Tarantino have grabbed onto elements of Godard's style, this kind of go anywhere abandon is still alien to watchers of Hollywood films, for the most part. The addled energy is infectious, and much of the film is exhilirating. The characters are doomed, as Godard has at least that much respect for genre. Somehow even that is worn lightly