One of the more interesting (and difficult !!) games in the "Sim" range is Sim Safari. The basic concept is that you are the manager of a safari park in Africa, and your job is to maintain the park, attract visitors to help pay for your conservation efforts, build facilities to keep those visitors happy, all the while maintaining a good relationship with the local visitors. You can plant different types of trees, shrubs and grasses for the animals, and purchase animals to keep in the park. The visitors especially love to see the "big 5" animals. There is a complex ecosystem you need to maintain and I found it really difficult to build a sustainable system. There is always something changing - one type of grass starts to dominate and pushing other grasses out, which upsets one type of animal that liked that grass; too many of one species of animal get eaten by other animals, upsetting the balance and so on. You have to maintain the entire foodchain, and it is a delicate balance indeed. You certainly learn alot about natural ecosystems, since you need to be continually researching what animals eat what and other factors. It is a fun, but frustrating game. Worth looking at if you have the patience to learn !