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.
Designated Hero: Space Chief helps save the kids from the aliens at the beginning, but does pretty much squat after that. He doesn't even get to finish the Neptunians off.
Of course, as his secret identity he does beat them. In fact, his civilian version is a lot more useful in every respect.
He more or less becomes "Too Little Too Late Chief" by the end. He shows up after a few dozen buildings have been blown up, probably hundreds dead, and even then, he takes his sweet time actually taking down the ships.
(singing) "Space Chief failed miserably and tried to cover up his shame."
Dude, Not Funny!: This supposed kids' movie uses footage of real World War II boming runs, during which actual, living human beings were killed, as cheap stock footage during its aerial battles. The uncut version even includes footage of an atomic bomb! The Mystery Science Theater 3000 crew in particular found this extremely appalling, which is why this film's riffing is much harsher than most other movies they took on.
Apparently, what really put the MST3K crew over the edge was the infamous "Hitler Building," a building with a gigantic mural of Adolf Hitler, which gets blown to bits during the movie's climactic battle.
What an Idiot: A very average summer storm apparently presents enough of a threat to the electro-barrier that the good Doctor orders that the city's main defense be turned off.
WTH, Costuming Department?: One of the few areas where Space Chief actually has a leg up on Prince of Space is the fact that his outfit isn't quite as ridiculous - but it's still very silly looking. Ditto the Neptune Men; not nearly as goofy looking as the chicken men of Krankor, but they're pretty bad.
When not in their clunky space gear, the Neptunians can be told apart from normal humans by wearing extremely heavy eye shadow and lipstick.