I don't think TDD, as such, is appropriate as a foundation for game development. Automated unit testing as part of methodology, sure, but too many of the key concerns of game development are subjective and untestable for testing to be the driver of development. How are you going to write a test for whether a game mechanic is fun? That a level is visually appealing? Even that a level takes a typical player around 15 minutes to complete? TDD fits situations where the maturity of a project can be measured in terms of its compliance to a specification, and that just isn't game development.

I don't think TDD, as such, is appropriate as a foundation for game development. Automated unit testing as part of methodology, sure, but too many of the key concerns of game development are subjective and not machine-testable for testing to be the driver of development. How are you going to write a scripted test for whether a game mechanic is fun? That a level is visually appealing? Even that a level takes a typical player around 15 minutes to complete? TDD fits situations where the maturity of a project can be quantitatively measured in terms of its compliance to a specification, and that just isn't game development.