How will people know if the prize has already been claimed? Wouldn't want to be wasting time only to realize I am too late. Especially, since it's the main selling point of your game...
If the mystery is solved, it will be announced here and on the official mystery page. For the moment it has not been so. Remember that you can also play the different free versions. The sale is mainly oriented to make the prize grow. Thank you for your interest in the game.