Can't help but think I would have preferred a movie that focuses on the hundred days and Waterloo. The final blowout battle is indeed impressive, but everything else fell a flat for me. The movie simply covers way too much, too quickly, and Joaquin Phoenix is not good in the role at all. Despite taking up a large portion of the runtime, the Napoleon-Josephine relationship was super opaque to me, and basically just provided moments to show how weird and awkward this sketch of Napoleon is. Maybe it would have been interesting if his personal life was contrasted with how charismatic he could be to the public and with his troops, but he's anything but charismatic in this movie.
This did get a pretty good laugh in my theater, haha.