In many ways, Napoleon Bonaparte is the perfect subject for a Total War game. He lived during a time of revolutionary technological advancement during which a number of powerful nations were in direct conflict with each other. The spectacle of war was at a particularly high point and Napoleon dominated the era with a forceful personality and ambitions that rivaled those of history's other great conquerors. And since Alexander and Caesar already have their own Total War games, it only made sense that Napoleon would be next.
In telling the story of Napoleon, Creative Assembly created a narrower, more tightly scripted series of three campaigns, four if you count the tutorial. You have to take the scripted nature of the campaign for granted, if only for the sake of the story telling. It certainly allows the team the chance to let players take on some of the specific challenges and situations faced by Napoleon himself. Whether you find yourself drawn into the rivalries of Italian city-states on your march to Vienna, or watch as your corps wither away in the harsh Russian winter, Napoleon is fairly faithful to the historical situation. Even the small minor missions and peripheral generals lend an air of authenticity.
