Bring in up to 20 of your friends and have a Kinect dance party, pizza & movie night or Xbox tournament.

Some questions and answers: (answers provided by the Microsoft Store)

Do you know if the store is closed during the party? 

No, this would be during store hours

Or do the kids have a separate room? 

They will have the theater space at the back of the store, it is not an enclosed space.

Is it really at night? 

No, it can be during anytime of the day depending on availability

Is it facilitated in some way or are the kids just "let loose" (not that that's a bad thing)?

It is facilitated to the extent that you can request the games that you prefer. We usually do not play M or R rated games during a private session.