As of today, Project Spark isn't downloadable on Xbox One or Windows. Microsoft made the call.
Current owners can continue to play with the game-maker for the time being, but online support will cease on August 12, 2016. From that point on, downloading other players' stuff or uploading your own will no longer be possible. "Be sure to download your favorite community creations and your own uploads if they are not saved locally," warns community manager Thomas Gratz.
"This was an extremely difficult decision for our team that we do not take lightly. When Project Spark transitioned away from active development last fall, many of our team members moved to other projects within Microsoft Studios. While this means there have been no layoffs at Microsoft, it also means it’s simply no longer feasible to continue the behind-the-scenes work involved with keeping Project Spark up and running with meaningful updates and bug fixes, so we have come to this hard decision."
Players who bought the the game's physical Starter Kit version between October 5, 2015 and today can at least look forward to some Xbox/Windows store credit.
Project Spark Sunset Announcement [Project Spark]... read more