Well, Napoleon was not great. Joachim Phoenix was great, as was Vanessa Kirby playing Josephine, but Napoleon as a whole was not.
The timeline was scattered, to say the least, and the pacing overall was pretty poor. It seems that Bonaparte just sort of kind of accidentally became emperor, and entirely without any agency of his own.
The war in the Peninsula was not mentioned at all. Not once. In spite of five French marshals — or was it six? — being defeated there by Wellesley.
Apparently Napoleonic battlefield tactics consisted mostly of disordered mobs of men running at each other.
No French attack columns at all, and not until near the very end of the film did we see some British troops forming square and then dropping back into line. Though to be fair, the aerial shots of those manoeuvres did look pretty good.
And although never even hinted at in any history I've ever read, it seems that Boney charged with the cavalry at Waterloo just before the Prussians arrived.
Also, the riflemen at Waterloo with telescopic sights on their Baker rifles made me snort air through my nose. Let us also not forget the complete misinterpretation of the nature of Napoleonic mortars.
I'm aware of the need for the massaging of events for dramatic effect in cinema, but this was a lot less massage and a lot more kitten-in-a-blender.
Ridley Scott may or may not have had the services of a military historian when blocking out his battle scenes, but if he did, it was not somebody who knew anything much about Napoleonic warfare. Or if they did, he ignored them.
Come to think of it, didn't he also give us D-Day landing craft in Robin Hood?