Yes, they're free to roam. They'll be a lot of people that don't like this and disagree with me but I wasn't that impressed with the club with a 3 year old in mind. Almost all of the rooms have computers, screens are everywhere. That's great for older kids and if they were touch screens they'd be fine for little ones but a keyboard and a mouse and unfamiliar software is too complicated for my 3 year old. My son likes to play with toys. The only "toy room" was Andy's room and the only toys in there were Mr. Potato Heads and the big piggy bank with big coins to drop in. There are no kind of building toys or action figures or dress up clothes for make believe. If there had been, I would have had a hard time getting my son out of there but he didn't like it much. On open houses, when I was there to play with him he liked it but otherwise not so much.
I watched a lot - I didn't find that the CM's try to encourage little ones to join in set activities. It's more of "we're doing this if you want to join us" and that's all. My son is not shy but needs a little more encouragement to try some new activity with kids he doesn't know. One day, I was watching through the window outside as he played with the Mr. Potato Heads (most of which were broken and pieces didn't really fit together). He was having trouble getting a piece to go in so he moved to where to CM's were just talking to each other and he was ignored. I saw him run out, ask the CM at check in to do it for him and then he went back to the room. I wasn't impressed.
For older kids or kids traveling with siblings or friends, then the kids club is good. They can find things to do or just run around. I don't think there's enough targeted for the very little ones. The only time they attempt to engage your child if they want to leave is if you tell them you are at Palo or Remy and then they will make an extra effort if the child says he wants to leave.
I will say that I was never worried about his safety when he was there. I felt it was safe and secure and had no concerns about him getting hurt or disappearing. I just wish there was more for his age to do besides computers and tv's.