I saw you added You Have to Win the Game. I was looking at it earlier trying to figure it out, because I think it's in the same boat as Heroine's Quest: The Herald of Ragnarok. They're both Free to Play games, but because they don't have anything to actually buy, there's no way to actually get the cards. There's a number of conversations about it on the game's forums on Steam. It looks like the same situation as Heroine's Quest - the developer didn't know he wouldn't be allowed to give away the cards without anything to sell.
Since I have not tested it ingame (and no DLC's are available on the store page) ... i will move the gamepage to the "Special Card Sets" (we will see if something will change with their card distributions)