Not so long ago I wrote a Puzzle game for Windows Phone 7 using XNA. The game was really simple and had no menu or state management. Luckily, I recently stumbled upon a sample on MSDN that describes the basics of implementing game state management using XNA.
To try things out a bit more I modified my existing puzzle game and included the sample game state management code. The results are pretty amazing!
Here's how my Puzzle Game for Windows Phone 7 looks like now:
If you're getting into writing games for Windows Phone 7 using XNA then you should really check out the Game State Management sample here:
I described in detail how I built my puzzle game application in an article called Writing a Puzzle Game for Windows Phone 7 using XNA. Try checking it out, I hope you find it interesting