Out side of kids camps there are so many fun activities that kids can enjoy in Aruba. I think a horse ride in Aruba as a first is a magical thing. What do you like to do with your kids?
I like taking them on hikes along the beach looking for shells and other things. All kids love ice cream as well! Walking them everywhere is a great way to tire them out.
Oranjestad has a mini zoo and some animal menageries. If you are not an animal rights activist who is opposed to that type of thing then I think your kids will enjoy it.