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: Ace is supposed to be the greatest hero of all time, but has some questionable moments, especially in the second season. In "Secrets of the Guardian Strike Sword" he calls out his rival for attacking him from behind, then later in the same fight takes advantage of said rival's distraction to attack him from behind. Worse, that same fight is supposed to be proof that Ace is the one who's really worthy of owning his Cool Sword. In "It Came From Outer Space," he refuses to entertain any notion of giving in to Melvin's demand to hand Lexi over. Even though she did blow up his star base, and Tech tells Ace they're hopelessly outgunned and trying to fight would be suicidal, Ace insists on fighting anyway. He even gets mad at Duck for suggesting that Lexi sacrificing herself to save the entire planet is the right thing to do. Before they found out Melvin was lying and had no intention of backing off once he had what he wanted. And Melvin wasn't even going to kill or torture Lexi, he just wanted someone who'd play board games with him.
Genius Bonus: At one point, Duck calls a saber-toothed tiger "Smiley." While this might at first seem to be a jab at the... well, "Saber Teeth," the actual name for a saber-toothed tiger is "Smilodon." That's pronounced "Smile-oh-dawn," for reference.
Ho Yay: Some fans read a degree of UST into Tech and Rev's friendship. In the second season, the creators may have picked up on this and, in an attempt to reduce it, had Tech and Rev show more animosity towards each other. However, this just made them look like a bickering old married couple.
The episode "Family Business" is a goldmine for this with a lot of Does This Remind You of Anything? moments. Rev's parents react to Tech as a stereotypical parent would react to their child's boyfriend, with not trusting him and with sarcastic insults.
In "Weathering Heights", during the fight against Weather Vane, Tech saves Rev and the following exchange happens:
Ace: (about Rev) I WAS going to save you next. Tech:I got impatient. (winks at Rev)
For some reason Rev always gets close to Tech at certain moments, places his hand on his shoulder and stays that way. No reason is given, he just does that sometimes.
Jerkass Woobie: Danger Duck. You can't help but to feel sorry for the crap he goes through, even if he did a Jerkass move beforehand.