Although the great gameplay of its predecessors remains, it's hard not to be a little disappointed with this game.
In the game you can play as one of eight european civilizations vying for dominance in the new world. The civs are the portuguese, ottoman, spanish, dutch, french, english, russian, and germans. In typical AOE style, each civ has their own unique benefits and units.
AOE 3 remains true to the fundamentals of the series. If you have played any of the previous games, the same basic gameplay holds. Gather resources, advance through the ages, build up an army, and trounce your opponent. This time around, there are only three resources to contend with- food, wood, and gold (coin). The developers have added a few new features to cut down on micromanagement which are much appreciated. No longer do you have to worry about drop off points or having your settlers walk all the way back to your town center to drop off resources. Now they simply go to the area and work. However, you will still find yourself tracking down idle settlers and retasking them from time to time - which does get annoying.
Gather enough resources and you can advance through the ages. Starting in Age 2, combat units become available. As you progress through the ages, certain new buildings and upgrades become available. You will be able to build more powerful land and naval units and develop upgrades to your economy. Unfortunately, the sense and payoff of advancing doesn't seem as large as it has in AOE 2.
There are a few new additions to the gameplay. You start off each game with an explorer, a hero type unit that is very good at revealing portions of the map. This character also has a few special abilities including a powerful attack that can be used to instantly KO a military unit or treasure guardian. There are several treasures located on each map. You must first defeat the guardians that watch over these areas and then have your explorer claim the rewards - these range from food, wood, and coin supplies to certain units or upgrades. Explorers are also critical in interacting with the various native settlements located on the map. These tribes normally keep to themselves, but your explorer can construct a trading post at their settlement and then recruit native warriors to assist your cause. There are also trade routes that appear on certain maps. Having your explorer construct trading posts along these routes will yield your civ resources or experience.
The final addition is a big one. AOE 3 brings in the concept of the home city. Each civ has a home city back in the old world which can ship units, resources, upgrades and other various economic bonuses to your fledgling colony. What you can send depends on what "cards" your civ has available. As you start the game, your home city starts at level one. As you gain experience by completing games and various challenges, your home city will increase in level. Each new level earns you a new card which you can select - each one has different features such as units, upgrades, etc. During the course of your game, you can play these cards to help your new colony. This adds a new level of strategy as many of these cards can shift the tide of battle.
Graphically, the series has had a huge facelift. It brings into play a new 3d engine which looks very impressive. You have the ability to zoom in, which limits your field of view but lets you really get a good look at the detail of the soldiers and other units. Performance wise though, this game did have a few issues. Despite having a relatively high end PC, my framerate still dropped to low levels during large battle sequences. This really made these battles somewhat annoying as the screen would freeze up and chug thus taking away from the scale and grandiosity of the battle.
The battles themselves were otherwise impressive - especially with cannon. In prior versions of AOE, they lacked true anti-personnel weapons. Most of the siege weapons were designed simply for taking out buildings and were uselss against troops. This changes with the addition of field cannon and falconets. These units are designed to take infantry and other military units out fast - and they are quite impressive in doing so. It's tons of fun to watch several of your enemies units go flying as your cannon unload a salvo into the midst of their ranks.
The series does have a single player campaign that takes you through three separate generations of a family. There is a common plot that runs through each age, but it is nothing that captivating. This was one of my biggest disappointments with the game. AOE 2 had several separate single player campaigns that let you play as a different civ for each one. They all were founded in history and were a lot of fun to play. There did not seem to be much variety in the campaign in AOE 3. Despite playing through 3 successive generations, the units had pretty much the same feel to them and the theatre/stage did not change much. I would greatly have preferred to play as several different european civs and relive the battles and adventures that they had in founding their initial colonies and expanding.
In summary, this game was certainly enjoyable. It held true to its RTS roots and was a very solid addition, but it didn't bring too many new innovations to this old genre.