Complex sentence: The series' animation technique is different from most American cartoons from the early 2000s; it was animated with traditional cel animation, at a time when many American cartoons had switched to digital ink and paint (possibly due to the 1980s settings).
Split into simpler sentences: The series' animation technique is different from most American cartoons from the early 2000s. It was animated with traditional cel animation, at a time when many American cartoons had switched to digital ink and paint (possibly due to the 1980s settings).