Sort of a nitpick but... During Lois' interview with Superman and Mala, Lois makes a reference to Wonder Woman. Not a real problem when the episode first aired, but from the Justice League cartoon continuity,it would be several more years until Wonder Woman debuted to the world.
Throughout the episode, the Phantom Zone projector's retrieval button seems to change positions. When Professor Hamilton released the worm-like creature the button was on the far left but, when Superman released Mala it seemed to be on the far right and when Mala released Jax-Ur it was in the center.
Lex Luthor: Now the truth comes out. No doubt Superman and this woman fancy themselves our rulers! No doubt they plan to populate the earth with Kryptonians, reducing us to slaves or pets!
Mala: (chuckles) An enticing notion.
Mala: I was mistaken in Superman's purpose here. I do not wish to rule these people. I wish to...help them...like Superman does.
Lois: (muttering) Yeah, right, and I'm Wonder Woman.
Mala: Excuse me?
Superman: (to Mala) I care for everyone... though you're pushing it right now.
Mala: I am Mala, Superman's second in command. I offer you my promise that to this world that I will follow in Superman's tradition of just rule with a fair hand.
Lois: I thought I was career minded.
On the Superman DVDs the episode order is slightly altered, placing this two-part episode after the original episode 3 (The Prometheus).
Superman has cobbled together a connection between the module sent to Earth with him and the orb he took from Brainiac in "Stolen Memories" - apparently, the module scans his DNA before allowing the orb to give out information.
Jor-El appears during the orb's recitation of Mala's crimes, but has no dialogue.