These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Crazy Awesome: this is a series in which out-of-character established superheroes and the Captain blow things up while being pursued by a Nick Fury spoof in an airship made from submarines welded together.
The aliens who meet the Captain are named Spa Fon and Squa Tront.note These terms came from the Weird Fantasy story "The Aliens!" and became a Running Gag across several EC titles, including MAD.
When Aaron recalls his time with the Celestials in issue 5, the one who gives him the "loser" sign with his hand is Arishem the Judge, a forgotten Kirby creation that can destroy worlds just by giving it a thumbs down with the "Cosmic Formula" enscribed in his hand.
During the penultimate issue beatdown of the Beyond Corporation's army of genetic freaks, 1960's Marvel character Hidden Man can be seen fighting them. Also seen are copies of Fantastic Four one time adversary, The Infant Terrible.