The physical casting is good (Roger is weakest, Freddie best), and the performances are AMAZING; the extent to which the four primary actors have inhabited their characters is borderline creepy, it's so good. The script, on the other hand...
The script follows a fairly standard three act formula: Things come together, things fall apart, things come back together. The first act is well done, and reasonably close to history. The second and third acts, however, are almost entirely fictional. Some of the events portrayed actually occurred, but the narrative that gives the events their emotional resonance has no basis in reality.
As a writer, this makes me uneasy. I appreciate that it is a good (if formulaic) story that is well told. But it isn't Freddie Mercury's story, it's just something that someone made up.
I remember a review of James Clavell's novel "Shogun" that included the phrase: "It's a well written, well constructed novel that includes something like a scene where President John Kennedy and his wife Marilyn Monroe watch the news of the attack on Pearl Harbor on television." "Bohemian Rhapsody" makes me think about that a LOT.