Please read this article, and see how hard it is to properly test your product, and even more when your product is a game!
Gamasutra: Anatomy of a Usability Test in Video Games (Part-1)
Gamasutra: UX Walkthrough: Anatomy of a Usability Test in Video Games (Part-2)
When teaching design, or consulting clients on design, I would love to have an assumption killer/alert available, so great to point out assumptions, to improve a product more and more, or make better decisions while developing a product or service.
