Values Dissonance: Killbison and a human farmer each give the finger a few times. In Japan, at least at the time, the gesture wasn't considered offensive, but it would be completely inappropriate in a kids' show in America and several other countries.
The Scrappy: Several fans dislike Jan as a very annoying kid, in contrast to the previous series' Shuta. While Shuta does contribute by being a Headmaster Jr., Jan is often seen as The Load by others.
They Changed It, Now It Sucks: This is more of the change of Star Saber in the Hasbro continuity. In the anime, he's a noble hero facing against Deathsaurus and his men and a Papa Wolf involving his adopted son Jan. In the comics continuity, he's a religious extremest who crushes enemies in the name of Primus. Unlike Ginrai, who had a less-extremes (being Crazy-Prepared and Properly Paranoid), Star Saber's characterization is questioned by fans of the anime and toys as it's felt his character is Ruined Forever.