Ben Daniels’s review published on Letterboxd:
The Godfather: Part II fulfills Michael's descent into the deep depths of darkness - before he's burnt in lava, dons a black mechanical suit and subsequently crushes all rebellions in the galaxy. His estranged son Anthony becomes the leader of a revolutionary force against his father's empire, and defeats him by blowing up his casino space station. Sounds silly and all, but Michael might as well become Darth Vader. However, this lunge into the abyss is handled far more masterfully than George Lucas could ever have. I don't even want to think about it.
And to cut a long story short, I have no definitive answer on which Godfather is superior. I believe this is a better executed film, but that I prefer the first due to Brando's performance of perfection. Michael's development in the original didn't feel as progressive, as he was explored less in favour of the more captivating Brando. However, here, his stubborn onset of stoic depression feels natural. He's lost all feeling.
I don't think I can say much more. It's just an absolutely masterful film and the series so far, if not the entire trilogy, places itself among the best of all time. It certainly has one of the best theme tunes out there - the sometimes smooth, sometimes riotous Italian grand symphony. It's a soundtrack of momentous scale - apt for a series of sprawling dynasty epics, the transitions between families during different time periods were seamless. Mistakes repeated. Legacies trodden on. People change, the circumstances vary, but the wrongdoings are maintained throughout history. Godfather: Part II is simply one of the best.