An epic retelling of Napoleons life
This is more or less a more polished, better designed Empire: Total War.
One of the biggest diffrences being the emphasis on generals being far more important. If a general dies, the ability to replenish (rather than just re-buy) units dissapears. Moral is lowered along with the ability to inspire. These features were far more basic and less important in Empire and were taken on board with Shogun 2.
Unlike Empire, this has specific story telling for a character rather than a natation with several more linear missions charting Napoleons life, from his infancy years as a teenager to his final years as an adult. Aside from being a history lesson it also acts as a great tutorial for newcomers, with the difficulty curve gradually increasing as the game charters more of his life. Interesting details such as the characters model aging can also be noticed.
Graphically, it is artistically and technically superior to Empire. The main map looks like an moving oil painting. The characters polycount are around 8 times higher than that of Empire. Smoke effects, chunks out the ground can see spectacular to look at during huge epic battles. Likewise the sound, like practically every total war game is incredible.
Overall, while this is less huge in scope than Empire, it is fundimentally a better game.
While it may seem similar to Empire, at the price it's going for now, it's well worth an "upgrade".