Base-Breaking Character: Crusher is either incredibly enjoyed due to his Large Ham behavior or incredibly disliked for the fact he constantly doesn't see his cheating ways lead to him failing every time. Special mention to his Manchild cries whenever he loses.
Ear Worm: The theme song. Arguably any song that appears throughout the show.
Fridge Logic: How do the monster machines eat if their mouths are just their grill...?
Idiot Plot: The point behind Blaze getting trapped in the cave in "Dragon Island Duel". Being a Voluntary Shapeshifter, he could've just transformed into something to free himself, but he has to wait until AJ finds him to realize such.
Memetic Mutation: The infamous "Call Blaze" app on the Google Store that scared kids became this. note Every time one would beat the game, Blaze would call you, threatening to stab you to death with his knife. Needless to say, this was a cause of concern for many parents with children who were left terrified by the unsettling call. The app has since been removed from Google Play.
Snark Bait: The show does have its fans, but unlike other liked shows outside its demographic like PAW Patrol, the show is made fun of due to its randomShocking Swerves (consisting of first Blaze and his friends developing the ability of beasts and then months later ROBOTSnote Which is an obviously poor attempt to compete with Transformers) and an obnoxious example the show is focusing more on selling toys than being a mixture of a kid's show and a toy promotion. It doesn't help that the STEM aspects are shoe-horned into every episode.
Almost every time there's an event at the Monster Dome, the music plays a beat akin to the backing rhythm to Queen's "We Will Rock You".
The song "Get to Work!" from "The Super-Size Prize" features a similar melody and music style to "Uptown Funk".
"Addition" is to the tune of "I'm Free (Heaven Helps The Man)" from Footloose.
The animals' Welcoming Song in "Animal Island" appears to be inspired by songs from various animal themed Disney films, specifically "I Just Can't Wait To Be King" from The Lion King, and "The Bear Necessities" and "I Wanna Be Like You" from The Jungle Book.
Said song is also to the tune of "Henry's Underwater Big Band" by The Wiggles.
They Changed It, Now It Sucks!: Some viewers didn't like a number of the changes after the mid-season 3 Art Evolution, such as having AJ describe the STEM concept instead of Blaze, a digital diagram of AJ's description appearing on his watch or Blaze's control panel instead of skywriting it, and not using his Visor View to see something faraway, instead having the camera panning to whatever is being spotted when he says it.
Although Blaze's friends get a lot of attention, their appearances gradually became fewer with each new season, almost as if they became Out of Focus. None of them even get a chance to sing a full song in the series (aside from a few brief moments in the first season).
Starla is suffering this the worse. She's appeared the fewest out of the main characters, only appearing no more than 5-6 times after season 1. She's also had the longest absence streak with a grand total of 14 absences, between "Toucan Do It!" in Season 3 to "Robots to the Rescue" in Season 4.
As a matter of fact, the fourth season contains the longest consecutive set of episodes that only feature Blaze, AJ, Crusher and Pickle — five in a row from "Officer Blaze" to "Blaze and the Magic Genie". It appears that said quartet of main characters have became the "official" set of main characters for the rest of the show's run, and the others have been demoted to recurring roles.
Watts was built up as Blaze's new Monster Machine friend, but she appeared very little in the fourth season, only four out of twenty episodes. Possibly because Melanie Minichino had a lot of work as the female announcer for Disney Junior, as well as her roles as Anya and Ava .
They Wasted a Perfectly Good Plot: The Monster Machines competing in a night race in "The Midnight Mile" would've been a good time for them to use their speed lights again (having received them in "Light Riders"). Instead, they race on a lit track with no lights on them at all, and thus, the speed lights have became Forgotten Phlebotinum all together.