Purple Man's character design has changed since his brief cameo appearance in "Breakout, Part Two".
The opening scene shows that the Vision had been under repairs since just after "Ultron Unlimited," but in the episode aired prior to this one ("Yellowjacket") he attends Hank Pym's funeral in perfect condition.
The triangular shield Captain America uses in this episode resembles the shield he carried during his debut appearance, in Captain America Comics #1 (March 1941).
Drake Bell also plays the part of Spider-Man in the animated series Ultimate Spider-Man.
Maria Hill mentions that the Hulk was originally grey-skinned. In the comics, the Hulk was in fact grey-skinned at first. However, his skin was eventually changed to the color green to difficulties publishers experienced in printing the color grey in comics during the 1960's.
The numeric code that Sif uses to identify herself to Scuttlebutt is "337." This is the number of the issue of the comic series The Mighty Thor where Beta Ray Bill (and Scuttlebutt) first appeared. The issue, titled "Doom!," was released in Nov. 1983.
Loki's punishment at the end of the episode mirrors his punishment prior to Ragnarok in Norse mythology.
Goof: In the scene right after Loki's power is drained, Captain America can briefly be seen with his shield, despite having it smashed by Loki during the battle. Then, when he returns to the Avengers' mansion, his shield is once again in pieces.
Thor's hammer, Mjölnir, is made of a metal called Uru.
When Iron Man splits up the team, he sends each avenger to a different ley line. Ley lines are veins of magic that run through our world connecting it to others.
The nine realms of Asgard, connected by Yggdrasil (the tree of life) are: Asgard, Alfheim, Svartalfheim, Vanaheim, Jotunheim, Midgard, Nidavellir, and Niflheim.
When Ultron hits Thor with his beam that appears to disintegrate him, it is similar to an event that happened during the Secret Wars in Marvel Comics continuity. Dr. Doom controlled Ultron during that war, and ordered him to disintegrate Thor, who actually used his hammer's power to teleport across the planet when Ultron's beam hit him. All that was left of Thor at the scene were cape fragments and his helmet, loaning to the appearance of his disintegration.
Ben Grimm (a.k.a. the Thing) and Johnny Storm (a.k.a. the Human Torch) of the Fantastic Four make brief cameo appearances as they help the Avengers fight the ice creatures. The Human Torch is seen saving Captain America and writing "you owe me one" in the sky with his flame trail. The Thing is heard shouting "It's Clobberin' Time!"
Fantastic Four member Reed Richards (a.k.a. Mr. Fantastic), who has the ability to stretch and bend his body, makes a cameo appearance towards the end of the episode.
The Black Knight (Dane Whitman) makes a brief appearance fighting Kang's ships over London.
Quinjets cost approximately $20,000,000.
As of this episode, Iron Man only has three different sets of armor available.
The suit Simon Williams wears during the procedure resembles his original Wonder Man costume from the comics.
The Quinjets can reach air speeds as high as Mach 8.
The Avengers' mansion has a beyond state-of-the-art science lab.