No matter how many original ideas you have and how well you created your design document, the end result of your game creation is going to vary, from being a complete flop to a masterpiece.
The optimum way to find the pitfalls of your game design, is through playtesting. This determines the entertainment factor of your game and amplifies the potential to become a great hit.
Roach Puppy Games has an article about Playtesting Super Robo Gems, a windows phone puzzle game. As the article suggests you have to expose your game to a lot of people, therefore you need to overcome the fear of bad feedback. You can’t deny the benefits of playtesting, thus emotions like embarrassment need to fade away.
It’s really vital to have your project tested by new people, because from a designer standpoint you usually overlook the pitfalls of your game design. A Gamasutra article about Usability has four techniques to share, in order to polish your game. The article suggests to focus early on in a usability technique, for financial and quality reasons.
Last but not least, The Game Prodigy provides us with a video Game Design Tutorial. Enjoy: