Kyle Bruce’s review published on Letterboxd:
Annette has all of the style and exuberance that you would expect from a film written by Ron and Russell Mael. It's funny, unique and doesn't really feel particularly indulgent in its eccentricities. Adam Driver and Marion Cotillard's performances are truly stellar, with Driver playing an edgy Bo Burnham-esque comedian and Cotillard shining as world famous opera singer Ann. The opening sequence is so joyful and does a great job of establishing what kind of musical Annette is going to be. Also, all of the music by Sparks is, of course, extremely funky.
However, not everything works. The visuals are beautiful but some of Leos Carax's artistic choices are very hit and miss, with some awkward techniques that feel out of place and some laughable portrayals of the films many ideas. It's also about an hour too long, which is one of the most infuriating mistakes a film like Annette can make. The story is relatively simple and the ideas are clear, but clearly Carax was hypnotised by Sparks' music and got carried away.
Overall though, it's pretty much exactly what it says on the tin. A rock opera with the unique vision of Leos Carax, who is known for making unique artistic films, set to a soundtrack by Sparks, a band known for making unique artistic music.