In the early 1980s one of the "killer apps" for the Apple ][ in schools was a text game (with occasional 40x40 lowres graphics) called "Lemonade Stand" (itself based on an earlier mainframe game) in which competing lemonade stands would make decisions on how much lemonade to make, what to charge for it, and how much to spend in advertising. We used to play it in class with one computer for the class and the class broken up into groups of 3 or 4 students who each ran a stand.