The entire X-Men were going to appear in the episode, but the studio didn't have the money to fly the voice crew of X-Men: The Animated Series (1992) from Canada to Los Angeles. Instead, the episode just has Storm in it since Iona Morris, the original voice actress of Storm in X-Men's first season, is the only X-Men voice-actress based in Los Angeles.
The Incredible Hulk/Dr. Bruce Banner was originally planned to appear on this 3-part "Secret Wars" storyline. However, the Hulk was unable to appear because The Incredible Hulk (1996) was airing on rival network, UPN. As a result of the Hulk, and all related characters, being unavailable to use in this animated series.
This episode is loosely based on the 1984 comic limited series "Marvel Super Heroes Secret Wars" (Vol 1) #1-12. All the heroes present also participate in the comics (except the Invisible Woman, who was pregnant at the time), as well as the Hulk, additional X-Men and Avengers, and even Magneto (on the good side for once). There was also the fact that Tony Stark participated as Iron Man in this adaption, whereas in the original comic book, Jim Rhodes was filling in for him at the time. Of the villains, only Doctor Doom, Doctor Octopus, and the Lizard were in the comic version, plus more such as Galactus and Ultron. The Beyonder did not take humanoid form, and Madame Web did not appear.
Robert Hays and Iona Morris reprise their roles as Iron Man/Tony Stark and Storm/Ororo Munroe from both Iron Man (1994) and X-Men: The Animated Series (1992), respectively, as well as previous guest appearances on Spider-Man: The Animated Series (1994). Quinton Flynn is the only actor to reprise his role from Fantastic Four: The Animated Series (1994), which also aired during the run of Spider-Man: The Animated Series (1994), but never crossed over before this arc.
As Lizard is a stand in for Hulk, Dr Conners being in control of his alter ego is a homage to Professor Hulk.