Do I have to be in the story?
Not if you don't want to. Come, have fun, chat with friends.
But if you talk with someone with glowing red eyes, they may be distracted by the guy in black armor who sounds like an iron lung.
How will I know who's in the story?
The participants in the story will wear a necklace with a pouch. It will be clear who's playing, whether or not they're wearing a costume.
How much control will I have over my character?
As much as you choose.
The story will be told through cards that will be handed out at the event. The cards will contain items your character knows; perhaps they'll include something about the other characters. What you do with that knowledge will be up to you.
The cards will be customized for each character. This is why I ask you to send me your description as soon as possible.
Do I need experience in role-playing or games?
No!
The rules are simple. You'll have plenty of time and help to learn. If you don't play any games, there aren't any rules to learn!
Also, the story will not be one in which one person wins while everyone else loses. It's intended that groups of people work together to accomplish goals. You won't be alone, unless you choose to play your character that way.
Do I need to know the story in advance?
No. Everything will be explained at the event.
If you're really curious, there's some advanced information here.