ScriptTD is an open source project that allows anyone to easily create a new Tower Defense game for the Windows Phone 7 platform, without any prior programming knowledge. The project lets you create new art & audio and edit some XML files to bring it all together into a polished game without having to write all of the code required to make the game work.
This video tutorial will walk you through each of the XML files that make up ScriptTD and how they should be tweaked to create your own TD game. You are free to submit your game to the Zune Marketplace and hopefully make a little lunch money. If you make a game from ScriptTD, please let me know so I can help get the word out.