Another issue is fun. Fun gives me a lot of unhappiness. Fun is a very difficult concept for educational simulation designers.
First, and this goes without saying, is that computer games are meant to be fun. They are designed to be fun. Computer games' raison d'etre is fun.
So naturally, those people who play computer games expect educational simulations to be fun. Many of the teachers and professors who want to bring computer-game-like educational experiences into the classrooms expect them to be fun, although not too fun. And some believe that all learning all of the time should be fun, or it's not really working.
There are a few issues, however.
No single game, just as no single movie, appeals to everybody. ...