Project Spark Facing Brightness Issues on Xbox One

Project Spark Xbox One beta users are reporting brightness problems on the game's forums. 

Player Spartacus073, who noted the problem reported that Project Spark is the only game where this problem is occuring, said: 

"I loaded up the beta last night and…so much black. It is like someone turned up the contrast and moved the brightness down as far as it can go. Even after I adjusted the brightness of the world the blacks were overpowering. Hopefully the option to control how much shadow/black is added because as it stands it is unbearable."

Developer SparkCarter said he'd seen numerous reports of this problem and has told "top men". 

Project Spark is Microsoft's forthcoming game-making platform which has already been tested in a PC beta and has been used to re-create the opening of Lionhead's Fable. The title will make use of both Kinect and SmartGlass on Xbox One and you can watch 50 minutes of Project Spark being played by the developers here. 

Are you in the beta? What do you make of it?