The comment which I linked was just an illustration. And I was talking about porting mobile games from iOS/Android to Windows Phone.

Besides that, porting wasn't easy even for apps which worked on Windows already. The API was quite different, and not in a good way. For example none of the standard Windows file I/O API was available. There was DirectX but it was DX11 FL9_3 which is not how you access GPUs on desktop Windows (you would either use DX9 or DX11 FL11_x).