This is a bit Disney-like. If you won't do the adventuresome Alternative Cave snorkel tour (which we highly recommend), they have tubing down an underground river that is fun. Swimming with the dolphins is extra money but it is a blast. The park itself isn't really worth the money, but it is a fun place.
The Mexican music show at night is really well done, but I'll warn you it goes on forever (2 hours +) and we would have felt rude walking out.
The Mayan ball game show was REALLY well done. Maybe this place was worth the money.