I would expect that the process of hiring a celebrity to be in your videogame has the potential to be very frustrating indeed. Take Sordahon from Two Worlds II as an example. Here, the people at Southpeak are doing everything they can to make the game awesome for Sordahon but it's just not good enough. And then he demands to have his girlfriend put in the game. The ego is unbelievable.
I do really dig this series of videos Southpeak has been producing for Two Worlds II. Of course, entertaining marketing is useless without a good game to back it up. But, hell, it can't be any worse than Two Worlds was, right?