Anno 1701 is a well done, but micromanagement-heavy, hybrid of Civilization and SimCity.
In short, it plays a lot like SimCity -- in real time, you monitor the health and welfare of your new American colony. Everything from resources (wood, textiles, iron, stone, etc.), to food (cattle ranches, farms, fishing), to entertainment (tea shoppes, coliseums, etc.) to military needs must be monitored and you must build the necessary buildings and units to meet those needs. You also negotiate and deal with potential allies and enemies, trading resources, fighting, etc. You have an adviser helping you along the way, and there are several good status screens you can use to control your efforts.
As you can guess, the management aspects of the game make SimCity look like solitaire... it's a lot of work, and doing all of that management on the DS' relatively tiny screens can be quite a chore. Still, it's all very well done, so if you like this type of game, you'll have a great time doing it.
Pros:
1. Very good production values -- great visuals, music, sound effects, etc.
2. Rich, complex game system makes gameplay very sophisticated.
3. Good opponent AI
4. Gameplay is optionally wrapped in a very well-done step-by-step goal/mission system.
Cons:
1. They cram an immense amount of visual detail into everything, which makes squinting at your little DS displays fairly intense. In these games, crises and shortages tend to come in bunches, which will have your scrolling around and clicking on your DS display like a madman.
2. The amount of things you have to track can be pretty overwhelming. This game is not for those that dislike micromanagement.
Overall, 1701 is a terrific game for those that enjoy empire building RTS games.