Just got back from a trip with a 12, 8, 5, 3 and 1yr old(not all mine). They all loved it, but the 3 and 1yr old went back to the room early and the older ones did the rides that the younger ones weren't tall enough for then. You might want to check the height restrictions before you decide. If the younger ones have to watch the older ones ride it might not make for a happy trip. If you could split up though, and let the older ones do the daring stuff while the young ones did the play areas it could turn out great. Do some reading on the different rides, if you are in a city you could probably get the latest UO guide from the local library. The biggest problem will be the height restrictions so be prepared.