I didn't even have to actually download through Amazon at all. I first clicked to download and install the Amazon utility, but before actually spending the time downloading the game with it, I went back to the amazon website and on my "Your Games & Software Library" section I was able to click by the game to get the Activation Key. Then just used the key and Steam to actually download the game.
I have all series of Total war games except this. I wonder whether i can download and play offline without internet? Also i am planning to upgrade my pc after a while, which i see some of the negative comments said there is a problem on getting it work. Any advise? - Offline gaming - Installing to different machine