It isn't about "games", for me, personally, and it never really was. It was about creating something- anything- far bigger than yourself. - Shigeru Miyamoto

Challenge for the player is the most important thing. In the Mario games for example, the player can go back and try to finish the game without collecting a single coin. I think great video games are like favorite playgrounds, places you become attached to and go back to again and again. Wouldn't it be great to have a whole drawer full of "playgrounds" right at your fingertips?

I think the first is that a game needs a sense of accomplishment. And you have to have a sense that you have done something, so that you get a sense of satisfaction of completing something. When I approach the design of my games, what I have to think about is how I'm showing a situation to a player, conveying to them what they're supposed to do. In Mario you keep going to the right to reach your end goal. In Donkey Kong you keep climbing up to rescue the captured princess. The last is the immersive quality of the game being able to feel it's a world you're immersed in, that you've become a hero. That you've become brave. Even if you're actually crying.

I could make Halo. It's not that I couldn't design that game. It's just that I choose not to. One thing about my game design is that I never try to look for what people want and then try to make that game design. I always try to create new experiences that are fun to play.