Nope, just ages 3-12 as long as they are potty trained. There are multiple rooms to play in and some are geared towards younger (dress up stuff, picture books, crayons and paper, etc) and some are aimed older with technology based games, computers, arts and crafts that take skill, etc. but all kids are free to go wherever and with whomever they want to play with.
They also don't separate kids for premium programming either, however my kids said tried to sit older kids with older kids and little with little for things like Stitch's space goo, the volcano thing, etc. however mine are four years apart (8 and 12) and sat together for everything no problem. I think they tried to group when it was single kids and the counselors were trying to encourage friendships
Also, each morning from 8-10 is open house so if they are in there you have to be with them. It's a great time for questions, looking around, etc. Secured check in starts at 10am.