The focal point of the movie is never fully explored or explained. The guy "reimagines" Beatles music sure, but why?
The characters are flat, stagnate throughout the movie, and the main antagonist (if she can be called that?) has a thinly veiled scheme to make money off the protagonist's music, but the thing was, the protagonist was already trying to do the same thing, so really he's just as at fault.
To call the romance subarc of this film "drama" would be a misnomer. In drama, something is at stake, and the actions of the characters place what's at stake in jeopardy. In this film, there is little to nothing at stake in regards to the main character's romance. It's actively toxic (the girl is always flip-flopping on whether she wants to believe in their courtship or what and as a result, is constantly stressing the main guy out while she threatens to leave him for good). Meanwhile, the main character will listen, dumbfounded to the girl ramble, his mouth agape in disbelief. It is extremely frustrating to watch these mannequins act out these scenes, as it does not take the characters, story or world in an interesting direction. Everything stays the same, then 5-10 minutes later they are doing the same excruciatingly painful song and dance again.
The high concept for the film is confusing but excusable until you consider the social and societal consequences for the whole world "forgetting" about X Y and Z. It's not just the Beatles that's gone. Apparently it's cigarrettes too (?!) as well as Coke and Harry Potter. None of those things exist yet somehow we are in the same place in society. Do workplaces not have smoke breaks, or is everyone smoking pipes and cigars? The movie never answers this and it's an untapped humor goldmine.
The Beatles are made out to be God's gift to the earth in this film and dissenters are either bundled into the "antagonist" bin or discarded. Confusingly, a few other people also remember the Beatles, and flew all the way across the world to see some kid play their songs. I understand that this movie "wants" to make some point about how music connects us, but this misses the mark for me.
The movie also glorifies the worst parts about music. The main character is so excited about his newfound fame, that the consequences of such aren't explored beyond the poorly done "will they won't they" subplot. Also, he's just doing this for the fame basically. His "coming clean" scene is all the less impactful since the world actually doesn't have any Beatles music in it besides his up until that point. This makes the climax fall flat for me.