Introducing Game Sketching! 11Oct06
You have a game idea. You know it will work, but you need to show it. After six months, you develop a working engine with pretty graphics and nice models, but only manage to produce a barely playable game.
Instead of focusing on the models and animation, focus on the game play.
Game Sketching is a new set of methodologies and tools designed to rapidly prototype a game and allow you to play it as early as possible.