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.
In a way, it almost makes sense for Hick's demotion to major in the series. As a major, his rank would make him a touch more approachable to Nick given that he's usually seen out on the field when compared to his original rank of colonel, even if a colonel would have more weight to be able to throw around. Plus, he has foremost knowledge of dealing with the likes like Godzilla compared to other military figures seen in both film and series, and thus would be more inclined to flexible thinking and follow the teams' suggestions.
In the film, most of the characters - notably Hicks and Phillipe - had difficulty pronouncing Nick's surname. Why is No Pronunciation Guide/The Unpronounceable averted here? Both had enough time to practice pronouncing it right.
Fridge Horror: Due to the events of the movie and episode 2, could you imagine what would happened if Godzilla wasn't spared, and having all kaiju loose, and not to mention the Tachyon invasion? It would be one hell of a Crapsack World.
In Serbia, where Godzilla as a franchise tanks horribly on regular basis, the series was popular enough to become one of only four American cartoons in history to be given a Serbian language dub. Particularly notable was that the entire series was given this, which had only happened once before. Ever.
Nightmare Fuel: Medusa. Sure, it doesn't actually kill you, but still...brrr...
Not to mention the Tachyon aliens. Not only can they control your mind, but if they actually transplant their consciousnesses into you, you'll end up slowly physically mutating into one of them.
-and when they're forced out of you at that point, they pretty much put you into a debilitating coma.
They turned out to be just escaping from C-Rex, but the mutant giant squids seen in the first two episodes are pretty scary, especially how they first appear as random tentacles coming out of the mysterious tar to grab people and pull them underwater.
Protagonist-Centered Morality: Kind of a strange case in the first two episodes, when Nick claims that the military was "Wrong" for trying to kill Godzilla Junior, as "He wasn't hurting anyone." This despite the fact that the previous specimen nearly leveled the city, and the current one is seen shooting atomic fire out of his mouth, even before the military showed up. In fact, Nick was previously advocating the creature's destruction, and was trying to force the military to do that exact thing. He gets a little better.
Rescued from the Scrappy Heap: Did this to the original movie... sort of. The movie is still considered... well, not that great, but it made the characters from the film, and Zilla Jr. himself, much improved from the original form.
Ugly Cute: Junior himself, when he figures out that Nick is "dad." Partly it's the look, partly it's the surprised noise the great lizard makes.
Unfortunate Implications: A bioweapon used against Godzilla rapidly wipes out his T-Cells. While the episode makes nothing of it, this is how AIDS works...
What Do You Mean, It's for Kids?: The series has an incredible amount of violence compared to the film. Such as the lead monster dismembering various antagonist kaiju, melting some of them, and even burning one alive. You have to wonder what the FCC thinks about this. It also showed military characters using guns that had the looks of real life guns (despite some Off Model issues) during a time when Family-Friendly Firearms was the norm for most US animation. And in the second episode, Animal flat out calls some soldiers "stormtroopers" to their faces.
What Measure Is a Non-Human?: More often than not, most authoritative figures or those with some power tend to always opt for the perspective of seeing the kaiju as simply monsters, animals at best (if that could even be considered "best", given animal cruelty cases). Examples include: the captain from Fort McKinley in "End of the Line" evoking with "a monster is a monster"; just seeing them as weapons as demonstrated in "Where Is Thy Sting"; or just "toys" tied to money, as seen in "Freak Show", "Winter of Our Discontent", and "Tourist Trap". Major Hicks is about the only authoritative person to at least consider alternative options and give the kaiju a smidgen of respect for their abilities.
The Woobie: Sydney Walker, the man who inadvertently creates the Crackler, in "What Dreams May Come". By the end of the episode you'll wanna give the poor guy a hug.