My main issue: The environmental message in the episode. It was too obvious. In any visual medium there is an unspoken rule: "Show! Don't tell!". If you're going to have an environmental episode, then have the characters actually cleaning up the pollution instead of just talking about it. Having a character actually do something about the issue at hand helps the message get through much more easily. It does not help when you have a villian pretty much say "Humans are lazy for letting even the smallest amount of pollution remain". When all the characters do is talk about an issue but don't do anything about it, it can sometimes be percieved as shoving it down people's throats. I know its a kids' show but seriously, if you don't have the heroes do something about the issue they're talking about then kids can percieve the issue as not important enough to warrant any effort by them and no lesson may be learned.
As for RoboKnight himself, I don't mind him. Though the music they gave played for his entrance reminded me more of RoboCop and his voice only served to increase this feeling. I was expecting a deeper tone to the voice and I really hope the voice actor puts more effort in to the role soon. This is PR, robots have been shown to have emotions in this universe, he shouldn't sound like he doesn't care. At this point, this is all I can say about him.