Aquatica has two rides where the whole family can go on together, there are also a few double rides. You can race each other on another and of course travel round together on the lazy and unlazy river.
I would say that Wet n' wild had more multirider rides than Aquarica or either of the disny parks.
You do have to pay to park at Wet N' Wild and aquatica - at disney water parks parking is free