Whereas from season 2 on, “Spider-Man” featured narrative arcs that often spanned entire seasons, the first run of 13 episodes were self-contained stories. Much of that helped the show to establish its world and characters, but it turns out there was more to it.
Speaking to the Marvel Animation Age (via DCAnimated), Semper revealed that he had a whole, season-long story arc prepped for the first season, only to be hindered by commercial considerations:
“I originally had planned a season-long story arc for season one, but I was prohibited from doing it because others had agendas that needed to be served first. Toys needed to be featured (those hideous Spider-Slayers), certain characters needed to be rolled out and introduced (the boring Hobgoblin) and so, in season one, I was limited in the things that I could do.”
The Spider-Slayers were flying killer robots, introduced in the second episode of season 1 and sent by Norman Osborne to take out Spidey. It wasn’t the most memorable storyline, although what kid isn’t going to love murderous flying tech? But once you know it was all at the behest of whoever at Fox and Marvel was in charge of selling molded plastic to kids (of which I was certainly one), it starts to make a little more sense.
Once the first season was out the way, Semper was given much more control, and from season 2 on, was allowed to play out his longer narrative arcs — which often took inspiration from the comic book storylines. As Semper put it, he was given “total control over the storylines,” which was, “when the real fun of the series gets going.”