The 400 Project

Video game developers have created a list of game design tips and maxims called the 400 Project. The original idea was to come up with 400 entries, I think, but the project apparently went dormant in March 2006 at 112. Contributors include some very well-known video game designers.

These are available at
http://www.theinspiracy.com/Current%20Rules%20Master%20List.htm (You can click on the name of this post.) There used to be a downloadable spreadsheet, but I don't see the link now.

Some of the entries are more or less repetitions of others, some are specific to video games, but this list is good food for thought, especially if you want to design standard video-games-as-interactive-puzzles.