The development of the interface for Amazing Animation was a challenging, unique, and a rewarding experience for our Interface Design Group at Claris.Given the constraints of a very tight timeframe and working with a user population we were unfamiliar with, our group was able to make numerous improvements which had a tremendous impact on the product's usability.This having been our first time designing for and testing children, we learned volumes about this unique user population.Design assumptions and testing methodologies used in adult products must all be reworked for kids.This paper describes the progression of Amazing Animation interface and points out the lessons learned about testing and designing for kids along the way.