I was hoping to be able to purchase the new content or a Steam upgrade as a thanks for supporting the Windows 8 version of the game but it seems I have to purchase the game twice (which isn't happening).There is no reason for it. Trying to force previously loyal fans into paying for another copy of your game so they can enjoy the full experience is beyond contemptible.
I understand that you've added content to the game and that is admirable but there is no reason why you couldn't just charge your loyal customers a discounted rate to receive this version of the game(Steam). If you really cared about your fans you could just give them or give them the option of purchasing a very cheap Steam keys to activate since they did already buy the game. Instead you've chosen the greediest path possible.
It appears that you mistakenly got into bed with Microsoft and got screwed. Now you're desperate and instead of doing what you can to build brand and customer loyalty you are chasing every dollar possible. Somehow ignorant of the fact that by not supporting your previous customers you are deterring new customers. So now you aren't getting money from me or the 3 extra copies I would have bought for my friends, others like me will skip the game as well and you aren't getting the small fee you could have charged to upgrade previous customers.
It seems to me that you might be missing out on more than a few dollars here. Good luck with that.I have added your company to my list of developers that I will not financially support and have informed several of my friends to do the same.