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.
YMMV: This Island Earth
The film contains:
Big Lipped Alligator Moment: While the context makes it clear that the whole "plane turns green and lands itself" was the Metalunans saving Cal because they needed him, the whole incident has pretty much no impact on the plot and is never mentioned after the scene ends. (Lampshaded in MST3K: "I don't want to talk about it any more"). If you'd cut from Cal flying his plane to Cal arriving at his lab, you'd never notice that something was missing.
In the uncut version, while building the interocitor, Cal gets a phone call from a mechanic explaining they couldn't find anything wrong with his plane.
Designated Hero: It's not that he's an unlikable character, it's just that Cal does almost nothing of consequence. He doesn't save any of the human scientists. He doesn't save Metaluna from its fate, or even bring back any useful knowledge to Earth. He doesn't save Ruth from the Mutant, since it just shambled after the unbelievably clumsy woman until it died. He was basically a tourist until he saved Exeter from the Mutant, even though he couldn't stop Exeter from being mortally wounded, and he didn't even finish the Mutant off or close the doors to the ship before it came aboard.
They Wasted a Perfectly Good Plot: An hour of setup, complete with competing viewpoints from Exeter and Brak, and once they get to Metaluna... it all becomes a "Point and shriek at the aliens" fiesta.
Took the Bad Film Seriously: Not really a bad film, but Rex Reason (Cal) and Jeff Morrow (Exeter) are both a few degrees too intense in their performances. Morrow especially throws in all sorts of melodramatic tics in an attempt to put Exeter's Anti-Villainy front-and-center.