At The Game Prodigy Blog I found a posting, that analyses the success-criterias of the “sandbox-game” Minecraft. Indeed, I think this is only a starting-point for a deeper analysis, but at least it is a good a starting-point!
This are the rules, they figured out:
“Catering to the Prolific 1%, and making sure that the Sandbox has a lot of Sand.”
Read the whole article.