It would be easy to be just bowled over by how glorious Empire: Total War looks. Creative Assembly's signature series has always been big on spectacle, and Empire is no different. The battles are bigger and bloodier, only now you have the smoke of muskets and crack of 12-pounders to accompany your march across the known world. Don't let the color of charging Cossacks blind you to everything else going on here though, Empire is a major step forward for the entire Total War franchise.
The 18th century clearly posed a challenge for the developers. The earlier games were pointy-stick affairs, emphasizing melee combat with the occasional overpowered archer and lots of sieges. In this era, there can only be a few types of "guys with guns" units, so you can't have a technology system that unlocks more expensive units. On top of that, this is the Age of Sail and the early Industrial Revolution, so you have to work all that in, too.
In fact, the resultant changes are so great, that there is a distinct possibility that Empire is just too big. The size really hits you when you run into the half-minute load times between the battle and campaign maps -- long enough to make you rethink the entire idea of playing general as well as king. Battlefields are immense and the enemy can effectively hide from your advancing lines. The strategic AI now has to juggle so many tasks, that it moves its development in peculiar directions: building three madrassas in an entirely Muslim province or trying to trade Transylvania for Cuba when the deal makes no sense for anyone. Not to mention the occasional suicidal war between Dagestan and Russia.
It's still worth sitting through these boneheaded campaign moves, because the strategic map is a much more interesting place now. Economic development happens outside of your provincial capitals. Towns and resources are scattered across the landscape, bringing wealth, knowledge or religion to your province. As the population grows, new towns and docks spring up, giving you new avenues to explore. Research limits how far you can upgrade these spots, and upgrades, in turn, open up new possibilities for research. The philosophical technology track is a double edged sword -- giving you new possibilities for revenue but also stirring up the masses. It is these connections between game mechanics that separate Empire from the rest of the franchise. Yes, the sea battles are cool, but they matter because control of the seas means control of trade. There's nothing worse than relying on overseas income and having it all vanish in an instant because someone plops a fleet on a sea lane. If you can't crack an enemy fort or beat him on the battlefield, you may pillage exposed towns until you are strong enough to fight or he is poor enough to quit. More than any other Total War game, Empire is a system of moving parts that fit together to build a world larger than cities to pillage and hills to climb. The agents are mostly useless (why should a scholar duel at all?), but they are thankfully less trouble to manage thanks to an improved interface.
The battles are fine, but they always are. The AI does a good job of using the terrain to its advantage, holing up behind fences or rushing into buildings for protection. It shows no hesitation in charging cavalry toward unprotected cannon, forcing you to guard your deadliest weapons on the battlefield. There is little reason to do more than point your guns in the right direction (ammo never seems to be a problem), but timing the bayonet or saber charge still gives the thrill of man-on-man combat. Even then there is a trade off, since there's always the chance of friendly fire if your horses attack an enemy under bombardment from your own guns. There are still too many sieges, and too few Waterloos.
Empire overreaches in parts, but I suppose that's the price of ambition. It will get even more ambitious once Creative Assembly adds the promised multiplayer campaign mode. But Empire's lumbering remoteness says something about the age it portrays: a century of mass armies and big ideas, the Wealth of Nations and age of steam. For all its problems, it's undoubtedly progress.