Unfortunately, but for the blockbuster visual spectacle, the film was disappointing. I can't see who it was aimed at, or what it was trying to convey. It was mainly about Napoleon's relationship with Josephine, but didn't focus on it enough to create any emotional engagement, and then spent much of the time on his biography that didn't contribute to the Josephine theme - a film about her might have been better. It said nothing new about Napoleon's character or his achievements.
It tried to tell the story of his life from Toulon to his death, but there is far too much to include, and the solution was to skip over periods of years and major events with no mention, and no feeling of time passing. No Marengo, no years of campaigning in Germany, no Spain, no Leipzig. Episodes came and went at speed with no development of reasons or consequences.
Napoleon was a political leader, but there was no hint of his politics or achievements, or the darker side of his rule. He was charismatic, but Joaquin Phoenix wasn't (though Napoleon's New York accent came across). He was a military genius, but that was hardly said, and there was no portrayal of his inspired tactics. The spectacle of Napoleonic warfare, with its huge columns of disciplined soldiers in their finery manoeuvring in choregraphed patterns, was absent, replaced by disorganised mobs running or galloping at each other and the impression that there were only few hundred in each army.
And for those of us interested in military history, there are all the usual Hollywood howlers and more besides: Napoleon leading cavalry charges and slashing away with his sword, exploding cannon balls, both sides in entrenchments at Waterloo, vastly excessive weapon ranges, no smoke, Austerlitz fought in the snow instead of fog and the famous sun of Austerlitz (and decided by breaking ice), armies reacting to a mumbled command or a wave of the hand, the geographically-impossible appearance of the Prussians on the British right at Waterloo … but my favourite cringe moment was when Napoleon planned his campaign and stabbed his finger at "Waterloo" printed in large letters on his map of Europe.
Only see it if you like movies for grand spectacle, not for performances, plot or history.