The Gravity Falls party will happen in October 2013, although it is not known for sure. You can meet Dipper and Mabel and go on a mystery with them. You choose which mystery from whichever episode you like, and you win items when you finish the mysteries. The items are:

  • ? pin
  • Dippers Cap
  • Treasure Map
  • Gravity Falls igloo
  • Mabel Stuffie
  • Grunkle Stan action figure
  •  Mabels giveaway ( with waddles even if she isnt walking him )
  • Dippers giveaway 

certain rooms will be themed like gravity falls

the clothes shop will be the mystery shack 

the dance club will be unknown