I think Megalon is a very shameless pandering to the kids, and to be honest, I don't think that was necessary. Which is why I prefer Gigan and the two Mechagodzillas, because the films are more adult with their wit (seriously, I think Gigan is a very clever film) whilst retaining the fun action for the kids. And Mechagodzilla is DARK, much more then any of Honda's films since Matango, and a really odd change of pace.

I thought Ken in Hedorah was nicely handled (like Revenge, there is the implication that Godzilla is a fictional character in this film until Ken brings him to life.) Rokuro in Megalon is just a bit too much like a member of the intended audience then he is a character which is why I don't like him.

They may be marketed to children, but the 70s films (besides Megalon and the 74 Godzilla) are in some ways much more grim and dark then their 60's counterparts, and I think we should stop trying to defend them by saying that they are "just for kids" but instead defend them on their merits, of which I think they have many.