Edit: here's a screenshot: https://dl.dropboxusercontent.com/u/2119748/Screenshots/Bildschirmfoto%202015-01-18%20um%2019.29.13.png
"We are down to you. Your pain and sorrow is our great pleasure . All your base are belong to us.".
The title of the site is also set to "Mac Robbery".
Same thing is on their Twitter account.
I don't think this is a prank - they were in the middle of a bundle sale which should have been running for the rest of today.
The background and the picture of Kim don't appear to exist anywhere else on the web according to GIS.
type killOverlay(); in console to get rid of the game and allow access to the purchase page.