In praise of messy design
Tanya X. Short of Kitfox Games wrote this wonderful article about messy design in games. She described three different types of messy: shaggy, baggy, and craggy.
A shaggy game design is one that forces the player to experience wildly varying systems and gameplay along the journey of the game. A baggy game design is one that has a wide, some might even say excessive breadth of systems. Craggy design is one that has surprising, some might even say excessive depth of systems.