The Godfather: Part II is beautifully directed and acted film, with an especially stellar performance from Al Pacino. The film is careful not to glorify the mafia and maintains their depiction as sociopathic power-hungry social parasites, who do not hesitate to opportunistically victimize the innocent in pursuit of their own gains. Also included in the film is many historical allusions as it takes place during the dawn of the Cold War. The setting of Cuba during one point in the film is an interesting reference to the political and socioeconomic situation of that country at the time.
The only obvious problem with this film is that it is split into two storylines... One of Al Pacino's character, Michael Corleone, in the "present time." The other of Robert De Niro's character, Vito Corleone, during his early upbringing in Italy and eventual rise to power in New York.
These two separate timeframes switch throughout the film and just make it feel a little disorganized. Would have been best to split those two timelines into their own films. By the end of the movie, The Godfather: Part II just feels slightly too long.