A few weeks ago, designer Brice Morrison talked about how a game designer outgrew games; since kicking off a flurry of discussion, he's returned to GameSetWatch with some in-depth answers to common questions and a challenge.
It's worth a read — a lot of issues readers raised are brought up, such as "What's wrong with games as simply entertainment? If you want intellectual stimulation, why not turn to something else?":
Nothing is wrong with viewing games as entertainment, but there is so much more that could be done! Games have the capability to be incredibly experiential because of their capability to provide interactivity.
As designer Dan Cook from Lost Garden wrote, it's the difference between hearing about the time someone decided not to pull the trigger, and deciding for yourself not to pull the trigger. Actually going through experiences yourself is much more compelling and personal than reading a story. The opportunities are too ripe not to pursue the possibilities.
Additionally, it's sad for someone who loved games while they were younger to have to turn away later in life because the days become busier. Other activities, sports for example, are still viewed as a worthwhile use of time, but only because of some other benefit in addition to being entertainment, such as exercise.
Video games also have the capability to provide the same kind of peripheral benefit. This doesn't mean entertainment should be shown the door, but I think even popularizing the idea that games could be something more is a good step.
He also appends a challenge at the end, a game design competition — it's pretty open-ended, and you can find more information at his blog.