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.
Juston was a base breaker in Academy and that has carried over to this series. The reason: The Sentinel. Many view it as a weapon of mutant genocide, despite the advances and developments it's made beyond that. To them, it is a sentinel and it must be destroyed. On the other hand fans of Juston's short lived Sentinel series are NOT happy at all with how the character was treated. Specifically Juston getting put through a massive Trauma Conga Line only to be killed off the next issue.
Apex, either you love her because of her ruthlessness or hate her for it.
Bellisario's Maxim/MST3K Mantra: The fans of Avengers Arena for the most part aren't too broken up about the character deaths and some of the technical plot issues, but are here for the overall story and character focus.
Broken Base: The biggest one in the whole Marvel NOW! re-launch. To the point where it got a mixture of cheers and boos at the normally friendly New York Comic Con reveal.
Complaining about Shows You Don't Watch: There was a change.org petition demanding the cancellation of the series before there were any previews. Some people who don't follow the series and only get news on big deaths judge it right away as well.
Many detractors criticize the book calling it a "meat-grinder" and gorn, despite most of the deaths being obscured by shadow (save for Nico's death), and the series being more about Character Development and Character Focus which is evident if one has actually read it, not to mention that the most of the kids didn't even turn on each other and start killing until the very end of the first run.
Creator's Pet: Apex is this in the eyes of many critics. She is supposedly one of the smartest people on Murderworld, but she was only successful because everybody she went against grabbed Idiot Ball much bigger than the one she's carrying around and because stronger characters have been subjected to The Worf Effect to make her look cooler. Also, Deathlocket, one of series initial Ensemble Darkhorses has been turned into satellite character, that only exist to make Apex look that much more interesting. Apex is also the only character narrative two issues, while some established characters (like Mettle, Red Raven and Juston) haven't got a single one before they died.
Cammi is another one - while nobody denies she is an experienced survivalist and Badass, she is also set up as an team leader in second arc and other characters, including those who actually are experienced leaders (Nico Minoru, Reptil), follow her without a question.
Other Braddock Academy kids, especially Cullen Bloodstone and Anachronism, are this to certain point too, because, with exception of Cammi, other characters rarely get a chance to show any initiative and are constantly Demoted to Extra and subjected to Worf Effect to make them look better.
And of course Arcade is one too, being portrayed as genius who managed to outsmart everybody in the Marvel Universe to have his sick game run for a month without anybody noticing, while in reality his plan worked only because everybody who could stop him have been either handled Idiot Ball or written as uncaring jerks. He is supposedly a clever mastermind who manipulated the cast into fighting each other to death for his amusement, while in reality he needs to make one ham-fisted interference after another to try make kids play his game, all of them failed.
Critical Dissonance: Inverted, the overall fanbase seems split on the title, but it's generally better received by critics and the comics industry, and Hopeless won the 2013 Harvey Award for Most Promising New Talent for the title.
Crowning Moment of Funny: As grim as it is, the series offers at least one big laugh: In #10, Chase transforms into Darkhawk to take on Apex when he overhears her plans to use the Sentinel and Deathlocket to kill the others. As he psychs himself up for the fight with a Rousing Speech, X-23 runs by...
Chase: Darkhawk is—
X-23:(Runs past, not even breaking stride as she yells at Chase) Stay!
Ensemble Darkhorse: Deathlocket was loved from her first POV issue. Cullen Bloodstone (Next Wave connection) and Anachronism (Axbro) are liked as well, even with little page space. Apex is also emerging as a favorite, which is pretty disturbing.
Fan Hater: Some of the more fervent Arena haters are particularly opposed to anyone liking the series due to the premise. Not to mention that some Arena fans to dish it out as well.
Fandom Rivalry: An interesting example be because technically speaking Arena is a sequel to Runaways and Avengers Academy, but Runaways fans and Academy fans for the most part do not like Arena fans, usually citing how they don't care about complex characters being killed off for cheap shock value. Whereas a lot of Arena fans didn't read the previous books and feel that's it a good story and just want to enjoy it without fretting over continuity.
Mettle and Hazmat's relationship (namely, Mettle's death in #1, and Hazmat subsequently falling into a grief-filled depression/rage afterwards) is more tragic as it's revealed that Hazmat's parents strongly disapproved of Hazmat seeing Mettle.
The kids were picked by Arcade because not many people would notice or care about their disappearances; and he could come up with plausible excuses as to why they would disappear and only communicate through texting/social media and if need be, be replaced by an android. Now consider the amount of derision Marvel and Dennis Hopeless got for considering these kids to be expendable enough to be killed off for drama...
I Am Not Shazam: The island that the kids are in? It's not called "Avengers Arena." It's Murderworld. Not to mention there's only 5 Avengers-affiliated characters in the entire story.
Internet Backdraft: Reviews are good to neutral to the series, readers are not so kind. It certainly has its fans, but it is far better known for sparking ire than anything else. Those positive reviews usually have to spend a paragraph or more justifying or defending itself from the fans who have been angered by Arena.
If she hadn't crossed it before the series ever began, Apex snapping Juston Seyfert's neck to steal his mech certainly crosses it. Particularly considering he had no way of stopping her from taking it while he was alive.
Moe: Deathlocket seems to be made for this, with her design, tragic backstory, and innocent behavior in the game.
Narm: "My boyfriend exploded all over me!" This one fails because of the Accidental Innuendo which turns a line where Hazmat (again) screams out from her heart into something laughable.
Never Trust a Trailer: The comic-book version. Marvel hyped the series up as a "deathmatch" book. The kids are pit against each other, but the main draw of the series is the Character Focus.
No Such Thing as Bad Publicity: Seems to be Marvel's Mantra for selling this series. In-house advertisements recommended it to fans of the young C-list characters of the 21st century, and to people who wanted to see them bloodily murdered.
Rooting for the Empire: Several fans are rooting for Apex to win or at least survive. Which is impressive seeing she is all to willing to play Arcade's game.
Snark Bait: For the detractors of the series, this is what the title is to them, and why they continue to read.
They Changed It, Now It Sucks: The reaction of many of the detractors to any sort of character development or continuity change of the non-original characters.
They Copied It, So It Sucks: A common phrase used to dismiss the series is simply "It's a rip off of Battle Royale / The Hunger Games."
They Wasted A Perfectly Good Character: Another fear the series fosters, as characters killed in the series may never be revived again. More to the point, the character of Red Raven who was brought out of obscurity only to be killed unceremoniously in the second issue, no lines spoken. Dennis Hopeless said he hoped to give her a focus issue, but there wasn't enough time allotted for it.
Tough Act to Follow: Avengers Arena is a direct follow-up to Avengers Academy, and uses five of those characters in the main cast. It also pulls characters from Runaways and Sentinel and Annihilation cosmic event, series with much critical acclaim and all with their own fanbases who look at Arena as being a disappointing follow-up.
Vocal Minority: There was initial outrage at the book's announcement, but most of that has quelled as Hopeless and Marvel have said that the reception has been more positive than negative as the months went by. Not that you would guess on certain forums...
Arcade, though his powers are only tied into the Arena thanks to Ms. Coriander. The attitude and the fact he hasn't been touched by any hero adds to this.
Apex, being a pretty blatant expy of Battle Royales Kiriyama, fits the bill pretty well once she gets going.
What an Idiot: Laura's hotly-debated actions against Apex in issue #10, where she tries to bum rush Apex head-on, despite Apex being armed with a Sentinel and Deathlocket under her control. It didn't work, but it was possibly the best chance to catch Apex off-guard and only failed because she wasn't fast enough.
Arcade himself. Yeah, kidnapping Wolverine's daughter/clone, a bunch of kids affiliated with in an Avengers sponsored school, etc. isn't going to get him beaten to a bloody pulp in the end. This one is so blatant it even gets lampshaded. And of course, he uploads all the footage on YouTube titled "What Happened In Murderworld?" so he blatantly confesses on the internet that it was all his doing since the X-Men and Avengers are very familiar with what Arcade has called his death traps. There's also the fact that his entire scheme to make himself a bigger threat was by making teenagers kill each other.