As a game designer, you'd just have to worry about satisfying two groups of people: (1) your team and (2) your players, but in most situations, you'd still have to consider your customer. Your client will almost always have strong opinions on how the game should look, behave, and play. It's crucial that you can work with these differing viewpoints. There are two types of game designers in the world: those who are satisfied and those who are irritable. The happy ones are either self-sufficiently wealthy or skilled at coping with their clients' strong opinions. The grumpy ones have a hard time coping with strong beliefs. Other times, the client will express views that are so illogical, stupid, and hypocritical that they defy belief. Some of the most inane stuff you'll ever learn can come from your client's mouth, and you'll have to deal with it somehow. And a lot is riding on how you perform: your client relationship, your designer credibility, your happiness, and your game. It's also essential to deal with bad advice. Demonstrate that you are serious, be organized, passionate, assume their point of view, create the pitch, know all the details, exude confidence, and so on. Be adaptable, practice, get them to own it, and follow up.