Recently, Microsoft announced its upcoming visual game design environment, Kodu, to be released “later this spring”. Combined with the level editor in Little Big Planet, these two should provide fascinating case studies for the project.
Another interesting piece on formal game design is the paper “An experiment in Automatic Game Design” by Togelius and Schmidhuber (find the paper in here). The authors created a program that would automatically create new games based on an underlying schema (or “meta-rules” or “axioms” as the authors call it). To evaluate the games, they had a genetic algorithm with a fitness function based on the idea of using learnability as a predictor of fun. Therefore games that are easy to learn but hard to master would get high fitness values with the algorithm, thus indicating a fun game.