The ages are just a suggested age.
That being said, I really dont like the Honey I Shrunk the Kids playground. It's a neat place, but waaaaay too easy for a kid to just disappear. There are dark tunnels that exit different places. There's dark staircases in those tunnels for a kid to fall down. There's stairs that go different ways. I lost my 5 year old there for a few minutes when we were there last week. I can duck down and go through the tunnels for a few minutes, but only for a few. It starts killing my back. And there's usually tons of people there. It would only take a second to lose a kid. Especailly if you are trying to watch more than one. I was watching my two year old and turned my back for a second and then could not find my four year old.
We really like Pooh's Playful Spot though. It's for the younger set, but it is wide open.