Both the versions of this game were released to an exclusively Japanese market. However, the NEC PC-9801 version has sharper graphics and the ability to use a mouse. Instead of abstract colors (to depict control of each square of the board), buildings are used to depict a typical Japanese residential neighborhood. A theme park is visibly shown on an island in the PC-9801 version to depict recreational opportunities.
Source: Wikipedia, "Leading Company", available under the CC-BY-SA License.