I am at my wits end, and about to demand a refund for AGK.
First, I was expecting to be able to download the AppGameKit player and test apps that way.
Then, when it became apparent that Apple rejected it (for shame, TGC, releasing the product before it worked as advertised), I have tried to build the AppGameKit player myself on the Mac using XCode (exactly the tool I wanted to avoid by using SGK). I have followed Lee Bamber's video tutorial on how to do this--from a pristine Mac--3 times!, and it continues to fail to build--spitting out code-signing errors. I have deleted all certificates and keys and gone through the steps EXACTLY in the order of the tutorial and IT DOES NOT WORK.
I am beyond frustrated and would not recommend AppGameKit to anyone at this point.