Let me start by saying I paid significantly less than the $20 price tag to get in here due to someone in the group being in the animal training industry.
That being said, paying $20 isn't such a bad price considering there are a good amount of cats to see and the place is pretty much empty - at least when we went at 3pm on a weekend day. I can see kids being pleased with the adventure as you do get pretty close views of the cats and the dolphins and there aren't tons of people that you can't see over. The underwater dolphin viewing room is great too!
Keep in mind there is a souvenir photo if you want for $20, and it's taken on a green screen, so try and avoid wearing green if you go.