The original came out 2003. The first couple episodes were flash animations. They were also parodying/emulating Johnny Quest from 1964 so the animation style was supposed to resemble Hanna-Barbera cartoons from that time period. In seven seasons over 20 years the style has evolved a little, but the basic style was established early. The writing and characterization are what set it apart, not the animation techniques.
9 Likes
