We just returned from a 3 night stay. When you check in, they will give you a list of activities that are going on during your stay. A typical day would have pool games in the afternoon several times. They set up and ask for volunteers from the audience (the pool). Most sessions were three games with teams of three or four in relay type races. The winning team of each game waits until the end and they do a group slime. Parents are sometimes asked to participate.
They have the Nick Live Family Style shows each evening in Studio Nick (inside). Two families are picked to compete in each show. There seemed to be two shows on the week nights and four on the weekends. You had to fill out a "casting" card and turn it in by 2:30 and "audition" poolside at 3:30. They only take teams of four that must include two adults and two children over the age of eight. We combined with another family to make up our team.
We were picked for the show, but didn't win. The winning team gets slimed. As the losing team, my daughter got to smear a pie in her dad's face. It was the highlight of her trip!
Let me know if you have any other questions!