The movie was originally going to be family friendly before higher ups asked for it to be PG-13.
The baseball team Jon faces is the Midvale Spartans. Midvale is the location, in classic comic continuity, of the orphanage in which Superman placed his cousin Kara to hide her identity as Supergirl.
The way Superman fixes the hole on the Watchtower is exactly how he fixes the hole on the tanker in the Superman 3 movie
The theme song used is not from Superman: the Animated Series.