Napoleaon is a great stratefy, but is exactly the same as empire, apart from you have less stuff to do!
GAMEPLAY: Exactly the same as Empire, apart from these few points. Firstly Napoleon runs on a slightly higher engine, so it does look a little better than the already gorgeous Empire. Secondly, if you are playing as France (making Napoleon the general) he cant die, he can just run away, and this is what breaks your armies spirit instead. But the differences end there. Gameplay is the same, the campaign length is the same (a good 30+ hours) well actually Empire is longer and has more reply value due to the greater amount of factions. So what I'm saying is, just read my in depth review of Empire and get interested in that, because it's the same game but better. If you have Empire, then don't bother unless you are a collector or a massive fan of the series.
GOOD: Its like Empire (Read my review on that instead)
BAD: Its like Empire (Basically the same game, but worse)
OVERVIEW: Get Empire.
Sorry for this shorter and less helpful review than normal, but I didnt see the point in writing more or less the same review that i did for empire.