This is our third Celebrity cruise (it is/was our favorite cruise line) but our first with a child. Our 3 y/o son is very social, loves going to daycare, is happy and used to staying with sitters. So we thought the Fun Factory would be a good experience for him. It wasn't.
First, the area reserved for 3-5 year olds is tiny. No room to run around. Mostly tables at which they color and do art/craft projects - not his thing. He likes more active, physical activities. Second, he told us that another kid "pushed him down the stairs." Ok, he's 3 and I suspect it was more like somebody pushed him back or rushed by him accidentally knocking into him. He insists the "boy in the red shirt did it on purpose," but really, who knows?
When I tried to address this issue with the staff at the Fun Factory, they got very defensive and launched into a litany of excuses despite the fact that I told them I understood that he was 3 and kids were rough, etc. I just wanted to find out if it was while the bigger kids were with them or what. Anyway, I was upset that they didn't offer assurances--or even listen to me--without interrupting with defensiveness and excuses. Bad juju for this mom.
After the first time, he said he didn't want to go back. But we tried it twice more for a couple of hours at a time. On the fourth time, he cried (he _never_ cries) and they called us to come get him. So my very social kid spent almost the whole 7 days with us.
This was a Spring Break cruise, so there were 650 "kids" (under 18) on board. There was no lack of kids to socialize with him. It was the place and the staff.
My unsolicited advice - if you have small kids, go on Disney or one of the other 'family friendly' lines. The passengers on board were very gracious and tolerant of him, which was a pleasant surprise. The Fun Factory, however, was a total bust. We'll be cruising Disney next time.