As a fan of historical movies, I was excited to see this when I first heard about it. Unsurprisingly, it did not live up to my expectations.
I know not everything in a historical movie will be accurate, but it's the effort to get close that counts. Evidently, there was no effort placed into historical accuracy of the battles. They got down the general concepts which could be found on the internet with 5 minutes of research, but there isn't any display of deep-diving into historical contact, only surface-level research. Again, it doesn't need to be perfect, but they should've done better.
Second, the plot spends too much time bouncing around. It's formed in these segregated scenes that are meant to resemble time transitions, and constantly switches between battles and Napoleon's love life. It seems like it can't make up its mind whether it wants to be a Napoleon movie or a soap opera.
Finally, I want to talk about the portrayal of the characters. Napoleon doesn't seem anything like what you'd think. The movie does a terrible job of explaining his arrogance and ego which are large reasons he ever rose to power. I think this is equal parts that Joaquin Phoenix isn't fit for the role and that the script is horrendous. On top of that, the movie does a terrible job of portraying the relationship between Napoleon and Josephine. I understand it's hard to describe EVERYTHING about someone in a couple of hours, but their relationship feels off. They seem in love immediately but there's not any evidence why they'd like each other. They confess their love but seem, in a way, afraid of each other. Countless times they confess their love but seem so stiff and cold towards each other. I'm no expert on Napoleon's love life, but I don't think this is at all accurate. It simply comes off as weird and creepy, and makes for a terrible experience, especially as it tries to incorporate itself into a primarily war-themed movie.
Overall, while Napoleon's story is amazing, I'd recommend saving your 2 1/2 hours and doing some research of your own on his story, or if movies are really your thing you can watch the Waterloo movie (which is much more accurate). Whatever you choose to do though, make sure it doesn't involve watching this movie like I did.