I've gotten wrapped up in theory and I find it to be counterproductive to the process of being an artist:
Its easy to push yourself to get to some ideal floating in space "the perfect game is some far away lofty goal"
Really you just want to make a lot of games and have fun making them. That's the key to any kind of art, make more and more art till you master it. Make good art, make bad art, make art that people say isn't art. You are the artist, not the critic.
Edit: when you are making games in an artistic way, even if people say your games aren't rich, you'll just laugh to yourself because you know that you made a work of art that got a reaction which is the ultimate goal of the artist.
Edit2: the only theory that is useful is one which makes it easier to create. If you are thinking about richness or some design framework, or anything at all really that isn't helping you produce work you are proud of try to throw out that way of thinking.