xbox.com marketplace website has never allowed you to "download" it.
I just purchased the Fun Labs hub without any problems from
http://marketplace.xbox.com/Product/Kinect-Fun-Labs/00000000... When I get chance I will load it up and try the in-app purchase of
Kinect Fun Labs: Kinect Me. Several of the Fun Labs games, including this one, have only ever been available through the hub.
I last played Fun Labs in February 2016 and other people have been earning achievements this month. For example 25th April 2016 -
https://www.trueachievements.com/achievementgamer.aspx?achiev... (page 812)
Edit: Just loaded up Kinect Me. It said it needed an update, which it downloaded, but then the screen went black and stayed black. Rebooted my Xbox and it worked fine the second time.
He's not a man. He's the holy Half-Dead who has seen the Underverse and returned with powers you can't imagine.