The design imperative represented in most games on the market is simple, and nigh-universal: give the player one thing to do, and develop and fortify this mechanic until it is strong enough to engage the player for the bulk of the experience. The addition of the odd mini-game (driving a tank in Gears of War, for example) serves to break up the action, but the focus of the design is still to provide a mechanic that can be successfully repeated for the entire game without becoming tedious.
Fable III represents the opposite extreme, and an entirely alternative design philosophy. Here is a game that provides a myriad of game options, with the caveat that each is relatively simplistic. The effect is that Fable III feels like a game made up of mini-games; an exploration mini-game, a finance mini-game, a combat mini-game, a social mini-game, and so on. The dilemma lies in whether players will find the sheer number of these mini-games to be sufficiently engaging as to offset the fundamental simplicity of the mechanics.