Apparently there is a 50% discount for the expandalone to Fallen Enchantress owners. So if you are interested then it may be in your favour to buy Fallen Enchantress in the sale. I think it's an interesting game, quite odd, and took me a while to decide I liked it, but I have concluded that it is rather good and has a nice atmosphere. My favourite feature is that the AI will use unit designs you've created in previous games if it likes the look of them, which can certainly beef up its armies. The AI (as of a few patches ago, I haven't played for a while) is a little haphazard in my experience, sometimes it plays rather well and sometimes it plays poorly.