The games may work fine, but Gamehouse embeds their games with software that keeps track of every keystroke you make in the game, and sends that information out to their home base via the Internet so they can track how you're playing your game. Check their EULA. There is a lot of information they collect about your computer, what's on it, and how you use it, that they really don't need to know.
I feel very strongly about this as well. In fact, when there is an occasional game that I want to play and Big Fish is not going to get it (like Mortimer Beckett and the Time Paradox), I wait for the boxed retail version and buy that instead, rather than dealing with EULAs like the one Jenny100 described above.