The classic God sim Populous is being re-imagined for the Nintendo DS. Originally released in 1989, the game places players in charge of a civilization with the goal of obliterating a neighboring race. The landscape is malleable, and the stylus is used to raise or lower the earth in order to create ideal living places for your subjects.
Areas begin as mountain ranges, but people need flat land in order to develop. You can also give general commands that determine whether your citizens act aggressively or defensively.