Project Spark will launch its Xbox One beta in January 2014. A Windows 8 version of the beta is due to arrive in late October 2013.
According to Digital Spy, Microsoft Game Studios general manager Dave McCarthy claims everything will be fully playable during the next-gen console beta. You can register for the beta here.
"You'll be able to either use that Crossroads mode to build something really quickly through story choices, you can do the blank slate editor, or you can take games that other people have built and then just edit them for yourself," he said.
Project Spark is coming to the PC, Xbox 360 and Xbox One. The Xbox One version will include exclusive features, including the recently announced ability to use the software and Kinect as a living room "mocap studio."