Head over to Project Spark website ad you will be greeted with a Form for Beta Sign-up.
Microsoft’s Project Spark just to remind you is a PC, Windows 8 tablet, Xbox 360 and Xbox One title with cross-play, where you can build, design games with your own idea and share them with fellow gamers. There has been lot of confusion & speculation about the project since the video demonstration we had during Microsoft’s E3 2013 press conference, much is unknown about except it allows you to navigate in an open world & sharing your games and remixing those of other players. So have a look by pointing your Browser to Project Spark Sign-Up.