Joshua Brown’s review published on Letterboxd:
Some of this doesn't work AT ALL. Some of it works INCREDIBLY WELL. Tone is all over the place and the plot is actually so simple that even if you loathe one scene the next still has all the potential in the world to win you over. I can completely understand why after being the in the Disney/Star Wars machine for a while that this is the pendulum swing Adam Driver takes, and of course he's great in it. Also, Simon Helberg is in his own little tragedy here and plays it all beautifully.
If you can, watch the Sparks documentary from this year before this. It will give good context for the music and show the probable reason that Adam Driver has a pencil mustache in the second half of the film.