Choose your own adventure

Why are some video games popular with people who don't play games?

Cari can sit and play the Sims2 for hours on a rainy day. She generally is not interested in games.
Other games that are popular with gamers and non-gamers are the SimCity series, Civilization, and Grand Theft Auto.

Something that these games all have in common, is the very open ended style of play. Games like GTA have a story, and preset missions. If you get bored with that, you can jack a car and do as you please.

I think that is something very appealing. YOU, the player, are creating your own story. YOU are using YOUR imagination, not the imagination of the developer. When Cari plays the Sims2, she talks about her characters, like she had been watching a soap opera on TV. She has control of the story at all times.

Reading about an upcoming game called, The Movies, prompted this post.
The Movies, is a game by developer Peter Molyneux. He is known for making these very open type games. In The Movies, you run a movie studio. Hire, fire, develop your own movie stars. Use them to make movies. You write the script, put together the scenes, and edit your movie. The developer is providing the tools, you provide the content. There will be plenty of content provided in the game, if you can not think of your own, but where's the fun in that?

I'm already trying to come up with ideas I will be able to produce in a game like that.
Something about a blogger that gains some super-human power. He will travel through the internet, spreading his ego-filled opinions. . . Sorry, that's not really an original idea.