40 minute video of Project Spark shows off creation

Project Spark for Xbox One, Xbox 360, and Windows 8 was one of Microsoft's most ambitious reveals at this year's E3. How does the game creation tool work? If you've been wanting to see more--a full 40 minutes more, to be exact--you're in luck.

Microsoft and developer Team Dakota gave a lengthy demonstration on Twitch (via Eurogamer). It takes you through building a generic fantasy scene, manipulating some goblins, and even how it built the E3 reveal video.