The sequel series to Ben 10, with management taken over from Man of Action by Glen Murakami and Dwayne McDuffie of Justice League fame.Ben "10" Tennyson and his cousin Gwen, now both 15 years old, team up with a reformed Kevin Levin, who is now 16, to stop various evil aliens. Seasons 1 and 2, which were initially one entire season, has them going off against the Nazi-esqueHighbreed, who are determined to eliminate all other races, leaving the "one true race". Compared to the original series, those seasons had a darker and more mature approach, as well as less filler and more continuity between the episodes. They also matured Ben into an Older and Wiser, more competentHero, giving him more control over the Omnitrix and amplifying his Chronic Hero Syndrome to almost Messianic Archetype level.Season 3 doesn't really have an Arc Plot, but instead tried to meld in bits of the original series, such as introducing villains of the previous series, putting more filler, severely diminishing Ben's maturity and generally toning down the dark tone. The closest thing to an Arc Plot for this season is Vilgax's attempts to finally get his revenge on Ben. This season was generally considered less good than the previous ones, mainly because it made Vilgax go through a severe case of Villain Decay.This series' Grand Finale set up the sequel series Ben 10: Ultimate Alien.This show as a whole is notable for starting a major Broken Base in the Ben 10 fandom: while a lot of fans complained about the often unexplained (or badly explained) changes both in-story and amongst the characters, and remained faithful only to the original series, many others appreciated to see Ben finally getting mature after all the Aesop Amnesia in the original show, as well as the Cerebus Syndrome it led to. It's commonly believed that the first two seasons were good to decent while the third one was disappointing. In the end, Alien Force was popular enough to last three seasons and allow the franchise to go on, spawning a similar sequel before it was decided to try going back to the Original Series' roots with Ben 10: Omniverse.As with the first series, Alien Force was given a Live-Action Adaptation film Ben 10 Alien Swarm. General consensus is that it's leagues better than the original's Race Against Time.
Aesop Amnesia: Particularly blatant with Kevin, who learns in "In Charm's Way" that Gwen still loves him despite his new, monstrous appearance. A few episodes later, he's back to wallowing in Wangst about how Gwen must not care about him anymore due to him looking the way he does.
A Nazi by Any Other Name: The High Breed, a race of aliens so obsessed with genetic purity that they seek to exterminate all other races, believing their gene pools to be "inferior".
While it is true that they are obsessed with genetic purity and believe all other races are inferior, the real reason they are trying to exterminate all other races is because they are all sterile due to inbreeding and are such huge dicks they want to take the rest of the universe down with them.
In "The Vengeance of Vilgax" this was actually the first weakness of one of Ben's new aliens (not counting Alien X) demonstrated. Spidermonkey attacked Brainstorm while he was busy prattling on. If Gwen hadn't told Ben to just absorb him with the Omnitrix he would've lost.
This could also be considered an example of Spock Speak
Apocalypse How: Alien X was unable to stop a Class X on Pluto (and a class 4 on the dinosaurs) due to its indecisiveness.
Arbitrary Skepticism: Kevin matter-of-factly informs Gwen her powers come from her alien bloodline. But he scoffs at Gwen's insistence her powers are magic-based. Turns out the Gwen's alien powers and magic are related.
The cops in Alan's hometown have no problem accepting the fact that he turns into an alien. But in "Inside Man", the police don't believe Tyler when he says he saw aliens. Keep in mind that Ben10 largely consisted of Ben, Gwen, and Max fighting aliens and other weird stuff, very publicly, for an entire summer.
Except those were not cops. They were DNAliens disguised as cops. By that point in the series, there's good chance none of them were human (At least, not anymore)
Artifact Title: As with the original series, Ben had much more than 10 aliens by the end of the series. He had the ten from the start of the series (sans Alien X), Cannonbolt, Diamondhead, Upchuck, Way Big, Lodestar, Rath, and possibly Ghostfreak, with a grand total of 16 aliens. And that's not if you count the Ultimate forms he gets in the Grand Finale.
Also, the titular Alien Force didn't exist at all until the end of the second season.
Additionally, Kevin 11 no longer has 11 superpowers (although he did stop using the nickname about the same time as his Heel-Face Turn).
Though his name is still Keven E. Levin....
Artistic License - Biology: The show features numerous human/alien hybrids, biologically impossible enough on its own. One of these had a nonhuman parent of a species made of fire.
The waste of a certain alien when it eats meat is said to be Uranium-1412; an isotope created by the writers, that not only has an incredibly high atomic mass, but also somehow explodes like dynamite when you step on it.
Maybe the impossibly-high atomic mass is what makes it so explosive?
A molecular mass of this magnitude would have a radioactive half life of (probably less then) milliseconds (means, after some milliseconds, about half of it split up on it's atomic level, another few miliseconds later, it's halved again... and again). Basically, not the "explosive" part is unrealistic, but the "when you step on it"-part: It should blow up in an nuclear explosion just for existing. Instead, it sends Kevin flying in a comical way.
Asskicking Equals Authority: In this series, this is an interplanetary law, allowing anybody who's powerful enough to beat the strongest person on a planet control over that planet. Vilgax conquers planets this way.
Beware the Nice Ones: Gwen Tennyson and Grandpa Max, besides the obvious fact that Grandpa Max is a Badass Normal, he's super, super nice to everyone, but when you push his buttons it's not pretty. Same with Gwen, she's the nicest of the Power Trio, but when she blows up, THINGS BLOW UP WITH HER. (Obvious Example "Max Out")
Big Bad: The Highbreeds in the first two seasons and Vilgax in the third.
Bizarre Alien Biology: The alien vacationers in "Fool's Gold" eat popcorn and excrete Solid Gold Poop. When they eat meat, they instead grow to giant-size and start eating everthing in sight before splitting up into a hundred copies. Ever heard of Mars? They used to call it the Popcorn Planet!
Blade Brake: Kevin does this on a collapsing space station in the episode "Vendetta".
Book Ends: In the first episode of the series, the first transformation Ben uses to fight is Swampfire. In the series finale, Ben uses Swampfire's Super Mode in the last fight of the series.
While Ben was wearing in the end Ultimatrix, last Omntrix form was also Swampfire. Also First season end too with Swampfire as last alien, just like in original series
Born Winner: Pretty much the big issue Charmcaster has with Gwen, with the whole "stole my spellbook" thing on the side. Charmcaster had to work and study for her magic, while Gwen was born half Anodite, "made of magic", and thus her learning came easier to her.
Book Dumb: Kevin, who is not only very clever and resourceful but who is extremely knowledgeable about alien technology and their inner workings, but when it comes to subjects here on Earth he's clueless, due to never actually going to school. Played for laughs in one episode where he attempts to light a match in a cave and doesn't realize the crates around his labelled TNT are filled with explosives, leading to a brief Looney Tunes-esque gag.
Brainwash Residue: Albedo copies Ben's appearance and Omnitrix. He also gains some of Ben's characteristics, like eating junk food. After having his Omnitrix broken, stuck with Ben's color-swapped form, and taken to prison, he shouts, "BRING ME CHILI FRIES!!!"
Breaking In Old Habits: One of Ben Ten's alien enemies was trapped in a duplicate of Ben's body. Among his complaints: the hands, which had an alarming tendency to touch "places I suspect are inappropriate."
Calling Your Attacks: In this case, calling your aliens. This may be a compulsion from the Omnitirix: Vilgax's blank DNA robots in the finale do it, but Negative Ben/ Albido doesn't when using the new Ultimatrix.
Rath does a few of these, with the best one being "Serious Sirius Buttkicking!"
The Cavalry: The season 2 premiere, when Ben, Kevin, a Highbreed, and a Plumber Magister are all captured by Michael Morningstar, now known as Darkstar, Gwen leads a squadron of DNAliens into the battle to stop him.
The Chosen One: Ben plays this up and milks it for all its worth. "Ben Tennyson, Wielder of the Omnitrix!"
Premium example in the episode where Charmcaster shows up: a Brainwashed Kevin is told to retrieve Gwen, so he deadpans a number of cover-up activities to get her out of the house (stock-car races, going on patrol, going to the planetarium). Instead of realizing that something's up, he reacts hilariously enthusiastically to every suggestion.
Ben: "I bet I'd be a great race car driver! * Vrrroooooom!* "
Combo Platter Powers: All of the Alien Force alien forms to various extents, particularly Swampfire, Big Chill, and Echo-Echo.
Conspicuous CG: Grandpa Max's mobile home, and pretty much any flying ship
Continuity Nod: Ben encounters other aliens and/or people which bear the same forms as his younger self was able to pull from the Omnitrix at the time.
Ben's soccer jersey is the same shirt design he wore during Ben10.
Several villains from the original series such as Volkanus (Though he appeared in an earlier episode) and Charmcaster have returned in Season 3, the latter having mentions to Ben and Gwen's encounters.
Time Heals starts off with Gwen back in her old Lucky Girl costume, "acquiring" the Archamada Book Of Spells.
Cursed with Awesome: As of Season 3, Kevin is stuck in an ugly composite form, made of stone, crystal, metal, and wood, with no way of changing back to his normal human form. On the other hand, now he can turn his limbs into hammers and other weapons a laMetamorpho, and has been far more effectual in combat as a result.
Cuteness Proximity: Even Rath has to admit that the marshmallow-looking alien baby is cute.
Discard and Draw: The series finale sees Ben destroy the Omnitrix via voice-activated self destruct. By the end, it's replaced with the Ulti-Matrix.
Diminishing Villain Threat: The Forever Knights were an ancient cult seeking alien technology to facilitate their world conquest. Now, it seems it started in trying to find tech to kill an alien dragon. Fortunately corrected in Ben 10: Ultimate Alien.
Vilgax received a new, physically less impressive design, was defeated several times by Ben.
After being a big threat in her debut episode due to powerful magic and cleverness, Charmcaster returns in an alternate timeline in "Time Heals", constantly boasting about how she killed that timeline's Gwen...only to get kicked around by present-Gwen on multiple occasions. It leaves one with the impression she only managed to kill her timeline's Gwen because she got lucky.
Egopolis: Vilgaxia? Seriously?? The only thing missing are ridiculous statues and art of their "king".
It was named by the people because he is surprisingly benevolent to his own kind.
Eats Babies: From "Con of Rath", Rath!Ben jumps down the Pantophage ruler's throat (to retrieve a baby prince, or course), then threatens to do it again and knit his intestines into a sweater if he doesn't agree to a peace treaty with the Luodans.
Homage to be sure. He actually says the (fourth) Doctor's iconic "I walk in eternity" line. And he's played by David "Ducky" McCallum. So is thus made of pure awesome.
He also resembles Dr Manhattan, with the glowy blue pulled out to form a new character. He even transports our heroes off Earth for a bit.
He may also be a homage to Walker from the Nightside series, owing to that pocket-watch with shortcuts to every where and when, and the smart suit he wears. If only he had a cane, though...
Besides the aliens, the Power Trio has its dynamic shift a little- Ben has become more like his grandpa, mature and level-headed, while the roguish and hotheaded Kevin resembles younger Ben. Gwen is about the same, though a little less bratty.
On top of that, Seven-Seven is just Six-Six with a better arsenal. In fact, in a marathon of the first series, they mention Seven-Seven is Six-Six's brother, so he's not so much an expy as he is an older brother.
The Con of Rath introduces us to a new Omnitrix alien: a broad-shouldered, feral savage with a quick temper, razor-sharp claws jutting from his knuckles, and a tendency to solve everything with violence. Sound familiar?
Not just familiar! He sounds Gr-r-reat!
The same episode also features a new villain, Jarret, King of the Pantaphage: a large, red, demonic overlord with long white hair. Kinda sounds like Trigon to me...
Actually, the Tiger motif, the wrestler nature and the aggression makes me think of Travis Touchdown. It also makes him look as if Kintaro had only two arms.
Darkstar in his debut resembles Slade with Raven's powers...technically he had the same powers he did as Morningstar, but with the FX now resembling Raven's Zinthos-mojo.
Extra-Strength Masquerade: Like its predecessor, the show is really inconsistent with regards to whether the existence of aliens, robots, and mutants is commonly accepted knowledge, or whether such things are supposed to be regarded as myth by the general public.
Faceless Goons: The DNAliens are a literal example, since they have no face
Family-Unfriendly Death: The pilot depicts a Forever Knight dying by being disintegrated in the explosion of his own dysfunctional weapon. As he dies, you can see his skeleton as he is disappearing. As if it was not enough, it is revealed mid-season that the DNAliens, the Hightbreeds' minions who the heroes frequently killed, are actually mutated humans themselves.
The premiere episode had a scene that averted the Bloodless Carnage trope on a TV-Y7-FV rating. Specifically, after a particularly intense fight, Ben looks to the stomach of the alien helping him, saying "your suit is leaking water". The alien puts his hand to the bluish liquid, brings it up within view of the camera, and gravely mumbles "that's not water" before falling down into his death throes.
Fanservice Pack: Myax from the alien force finale. She went from basically pre-exploded Vilgax with a female voice, to suddenly growing breasts, and resembling Max's old flame Xylene in appearance.
Fantastic Racism: The Highbreed, who served as Big Bad of the first two seasons, looked down on any and all non-Highbreeds, especially humans, viewing them all as mongrels and vermin. They didn't even try to hide it: the Highbreed Commander that Ben fought in the pilot episode openly and relentlessly insulted him with remarks like "filth" and "scum", and when Ben bit his hand to escape a Neck Lift, freaked out and declared that Ben had "infected" him. Unusually, they were content to merely avoid contact with other species in the past. The reason they started their campaign to "cleanse" the universe is because they discovered that their species has become sterile and will go extinct in a generation or two. They just can't stand the idea of "inferior" beings outliving them. However, using the Omnitrix to hybridize them and cure their genetic damage, Ben convinces the Highbreed to drop their villainous ways and reform.
Filler - The entire second half of Season 1 (From Ep 7, "Pier Pressure" onwards). Season 3 is also riddled with this.
Flanderization: By season 3, Gwen went from calm, mature and responsible with occasional Tsundere outbursts to stern, serious, but short-tempered, stubborn, moody and snarky.
In the second episode, the plumber agent saves Kevin's life, but tears his suit - since he doesn't breathe air, he dies. This is considered part of the reason Kevin agrees to help Ben for the rest of the series.
Later on Max uses a weapon to send all of the D.N.Aliens and the Highbreed in the area, along with himself to the Null Void saving Ben and his friends.
Before that Devin Levin saved Max by jumping in front of a lethal blast from Ragnarok
Idiot Ball: - Ben's parents in "Grounded" apparently have a matching pair. Yes, Ben lied to you. Oddly enough, not actually the most important detail in that conversation. That freak-out you're currently experiencing? That's WHY he's been lying to you.
Not to mention Cash and J.T. in "The Gauntlet"
J.T.: You mess up Kevin's car, and everyone will know you're bad-the baddest in town! They'll be talking about it for years.
Albedo for believing Vilgax when he said he was no longer interested in the Omnitrix after years of pursuing it.
Everyone on this show is gonna get a chance to hold the Idiot Ball at some point.
Ink-Suit Actor: According to a source, Ben's parents in this series were designed from and voiced by their live action counterparts from Race Against Time.
Instant Expert: Alan the half-Pyronite - in the teaser, he's having trouble flying. By the end of act 1, he's trick flying and Jetray is having trouble keeping up with him. For that matter, he flies better than Ben ever did onscreen as Heatblast...
Not to mention Ben seeming to automatically know what his powers are when transforming into a new alien.
This could be because of the "updates" the Omnitrix received at the premiere, he had no clue in the original series.
Large Ham: Omnitrix-newbie Rath. To quote his lesson for the episode:
Eating. Babies. Is NOT. COOL!
Lawful Stupid: Alien X again. His mind is typically made up of a voice of rage and aggression and a voice of love and compassion. Without Ben as the voice of reason, they are too busy debating what to do next for Alien X to even move. This is not as in "just stands there" as much as it means "frozen in the exact same position, not even able to walk or blink." And they have been doing this since at least the extinction of the dinosaurs.
Leitmotif: A snippet of the original Ben 10 theme song describing Ben can be heard in the theme song.
Loyal Phlebotinum: The Omnitrix proves to be this after Vilgax successfully steals it, but Ben is still the only one who can activate it.
Magic Pants: AKA The "Broadcast Standards and Practices Modesty and Y-7 Rating Preserver." AKA, Kevin's unexplained black underpants in season 3.
Magic Skirt: Though Gwen wore tights, too, so even if her skirt were to fly up, we still wouldn't get a Panty Shot.
Make Me Wanna Shout: Echo Echo's other power, besides duplication. They can also transfer the concussive wave across speakers or amplify it by shouting through each-other.
The Man Behind the Curtain: Double-subverted with D'Void, who turns out to be Dr. Animo within moments of talk that D'Void was invincible; he shook off Ben easily, thanks to newfound power, which turned out to be from the drill, which of course was later destroyed
Matchlight Danger Revelation: Subverted in one episode where they're in a dark cavern & Kevin lights a match to see, revealing that the chamber is filled with crates of TNT. Gwen immediately blows the match out before it can set off the explosives. Annoyed, Kevin tries to light another match, only for Ben to blow that one out too. Apparently Kevin's not a very fast learner.
Subverted in the season 3 premiere, where Ben goes Swampfire...in the methane-filled sewer tunnels.
Pretty much all the alien species names, such as Rath the Apoplexian.
The High Breed call themselves that because, obviously, they think their race is superior. However, it takes on a second meaning when in order to allow the species to breed, Ben uses the Omnitrix to mix their DNA with a variety of different alien DN As, making them a Hybrid species.
The Ulti-Matrix, which can evolve it's aliens to their highest forms.
Kevin's full name is revealed in Alien Force. Kevin means 'handsome', while his middle name, Ethan, is 'strong'. His last name, Levin, is a form of Lewin, which means 'beloved friend'. Guess how Gwen sees him?
Albedo is the measure of the reflecting power of a surface, just as Albedo is a reflection of Ben; albeit in a funhouse mirror.
Never the Selves Shall Meet: In Time Heals. Averted when Gwen travels back to the season premiere to keep Kevin from mutating, and literally when she arrives in the new present, where her alternate self was previously killed in battle by Charmcaster.
New Super Power: Mostly averted (many new aliens are simply combinations of the older ones) until Lodestar shows up a few episodes into the third season.
Nice Job Breaking It, Hero: Quite literally in the Season 3 when the trio overload the watch trying to get it to access more alien forms (granted it was well intentioned). Gwen also pulls one in "Time Heals" via time travel.
Nigh Invulnerable: Alien X. Good thing too, considering the Voices are too concerned with debating to walk.
No Kissing: Gwen/Kevin shippers have speculated through the entire season if/when Gwen and Kevin would get an on screen kiss. Dwayne McDuffie continually stated it would always stay off the airwaves. Subverted. It eventually happens at the end of the series finale. Kevin regains his human form after the original Omnitrix was destroyed and Gwen indulges in a "victory kiss".
Omniscient Database: Somewhat subverted; the Codon Stream on planet Primus is the actual source of the Omnitrix's DNA samples; the Omnitrix itself is a sort of wireless reciever.
One-Winged Angel: Both the heroic and evil versions. And the heroic version, Alien X, is both played straight and nastily subverted.
Palette Swap: Albedo becomes a non-videogame example after his copy Omnitrix is damaged.
Papa Wolf: Rath, when he rescues the Luodan Prince Tiffin.
Paradox Person: A monster from 50 years in the past that accelerates time destroying a town and Ben and the gang is told the creature does not hold order in the time stream by a being whose existence himself is like a paradox.
Parental Bonus: In the episode "The Gauntlet," Ben brings juice for Kevin and Gwen. Kevin dismissively tells him to go away, so Ben sets the drinks down, but on second thought grabs Kevin's drink and says, "No juice for you!" This is a reference to the Seinfeld episode "The Soup Nazi," in which the eponymous character's catchphrase is "NO SOUP FOR YOU!" when proper etiquette is not followed at his soup stand.
Penal Colony: In the episode Voided, it's revealed the Null Void was originally created by the Galvans as one of these, and while there are still prisons there for the more dangerous criminals, several land masses are actually inhabited by the now peaceful descendants of the original prisoners.
Pet the Dog: In two episodes in a row, a featured villain (Charmcaster and Vilgax) save the life of a child (Charmcaster levitates a boy away from being hit by a truck, and Vilgax defends one of his species' children from Ghostfreak's minions.) The two still engage in evil-doing afterwards, though.
Plot Hole: A number of these have popped up in the series and usually come with a Retcon, but others aren't patched up. One example being Vilgax getting the Omnitrix and being unable to use it. Even though in the first series he had extensive knowledge of the Omnitrix, even in the series finale of Alien Force he had better understanding of it than in the earlier episode.
There are a few situations where Ben transforms in public without compromising his secret identity. This is particularly the case with "The Gauntlet", where a fight scene happens near a Mister Smoothy, with either none of the townsfolk leaving the scene, or the few that stayed being there long enough to see Ben transform into Chromastone or back.
Plucky Girl: Julie. Gotta give the girl some credit for how she handles the whole alien thing.
Poor Communication Kills: Gwen never mentions to her Mode Locked boyfriend, even in passing, that she's been constantly searching for a way to help him. Obviously this is because...er...they couldn't have a fight about it otherwise?
Pride Before a Fall: Ben's cocky attitude, which began coming about after saving the world from the Highbreed, is a prime example. His ego results in the Omnitrix resetting to its faulty first series self, as well as turning Kevin into another amalgamated monster.
Product Placement: Most likely accidental; Mr. Smoothie is a real franchise of juice bars in New York, Pennsylvania, New Jersey, Virginia, North Carolina, and coming soon in Ohio.
Punny Name: One of the Plumbers' Kids has pointy spines...and is named Pierce.
Kevin E. Levin, anyone?
Rath's species is known as an "Apoplexian".
Reality Warper: Alien X. Too bad the Voices are indecisive to the point of inaction.
Reasonable Authority Figure: When Ship is being repossessed, Kevin and Ben go to the Judge who issued the order, one of Raff's species. Despite Kevin insisting on doing the talking, Ben tries to smooth talk his way out, and ends up making the situation worse, and destroys the Judge's bench. The Judge also recognizes Kevin, having tried him for numerous crimes. Despite all these mishaps, the Judge mostly keeps a straight face, and rules in favor of Ben, because he did just save the universe.
With how different many of the 'returning' aliens look in Season 3, it could be Ben dialed one up and had a cloudlander moment so he didn't recognize the differences.
Remember the New Guy: Ken, Gwen's older brother who was never mentioned or even suggested she even had any siblings up to that only episode he has appeared in. After that he is never mentioned again. Suggesting he was created solely to give Max a reason to come out of hiding.
Pretty much everything about Kevin: Kevin's dad is supposed to be a Plumber that he got his powers from, but it's specifically stated before that his powers were a mutation that nobody knew the cause of, and it's what caused his parents to kick him out. His powers also changed, now simply absorbing a shell of material around his body instead of absorbing, storing, and redirecting energy (though Word of God stated he's always been able to absorb matter and energy). Also, when he mentions his Plumber father, he says that he's talking about his "real father." and in the first season finale of Ultimate Alien, it's revealed that Kevin's stepfather is actually a good person, and that Kevin wasn't kicked out, but went insane with power, destroyed the house, and ran away.
In "What Are Little Girls Made Of?", it was stated all magic is really reality-warping scifi-powers caused by aliens, though they've since backtracked somewhat on this and Gwen even still has Charmcaster's spellbook and now the Archamada Book Of Spells. McDuffie also said Hex and Charmcaster are human practitioners of magic, though it's since been revealed that Hex and Charmcaster themselves are from another dimension.
Related to this is the status of Verdona. In "What Are Little Girls Made Of?", we find out she's alive (and the reason for Gwen's powers). In the original series, in the episode, "The Visitor", it's implied (though not stated) that she was dead.
In the original series the Omnitrix aliens' names were just something Ben made up himself, as evident when his future self said he quit naming them because he gained so many. In this they're apparently "file names" the Omnitrix stores them under as evidence by the case of Transformation Name Announcement. Then again, Ben actively names Brainstorm after transforming into it the first time, and shouted the name after transforming each time after that. And Albedo, who creates a copied Omnitrix based on Ben's, doesn't shout out the names. So it's almost certainly still just a personal quirk of Ben's.
The Plumbers themselves: In the original series, they were a defunct The Men in Black-type organization, and all human (and many were very anti-alien) with Xylene only being an honorary member. In AF, they're now a still-active interstellar police force, and pretty much all of the known human members married aliens.
Ret Gone: At this rate, the Ben 10,000 timeline has become an alternate one.
Sacrificial Planet: In the episode "Fool's Gold", mischievous but harmless aliens come to a village every 17 years where they eat massive quantities of popcorn and defecate solid gold. When the town's mayor gets greedy and kidnaps one, he gives the alien a steak, causing the alien to grow into massive size and defecate unstable uranium. The alien's friend tells Ben that Mars "used to be called The Popcorn Planet" before his kind came there.
Same Character, But Different: Pretty much everyone. The most drastic change is with Kevin. In the first series, he's an eleven-year-old sociopath who couldn't care less about crashing a money and passenger train together, killing hundreds of people for some cash. Then he's suddenly a love-struck teen and friends with Ben!? No amount of Character Development could explain having a completely different personality...although the next series tries it's luck at it.
Self-Deprecation: The finale has Ben talking about how his favorite show changed and became unpopular, in the process highlighting pretty much every complaint about this series compared to the original.
Additionally, the changed show-within-a-show had gained a new subtitled - Hero Generation, the working subtitle of Alien Force.
At the beginning of "Undercover", Ben is wary of Kevin testing the teleporter with a banana, questioning what would happen if a fly landed on the banana during the test, turning it into a "killer banana fly", a direct Shout-Out to The Fly.
Straight for the Commander: In the season 1 finale, the heroes, failing to stop the Hightbreed invasion, end up using their portails to reach the Hightbreed Supreme himself. Played with in that they don't end up killing him, but rather finding a peaceful solution to end the conflict.
Strange Bedfellows: Very briefly in the 2nd season premier: Gwen and a troop of DNAliens against Darkstar. Later, Kevin and Darkstar together, only for Darkstar to predictably turn on Kevin in the end.
More recently, the Power Trio and Vilgax against Ghostfreak.
Subverted Suspicion Aesop: Kevin is very suspicious of Ben's first invitation to the Plumbers, but both Ben and Gwen calm his fears. However, 1. Ben is oblivious, 2. Gwen turns into a victim, and 3. it's Mike Morningstar, who'd go on to be recurring villain Darkstar.
Super Dickery: "Above and Beyond" is about the Plumbers' Helpers trying to rescue Grandpa Max, who's being attacked by an out-of-control Ben. Of course, Ben hasn't really gone rogue. The entire scenario (sans crashing space station) was really just a test for the Plumbers' Helpers.
Take My Hand: At the end of "Voided", Ben is in the Null Void and Gwen reaches out to pull him through a portal back to Earth. She's struggling...and then Kevin appears and grabs Ben's other hand.
Tertiary Sexual Characteristics: Lampshaded by Kevin when he mentions the green alien the trio has taken to calling "Tiny" can't be a girl because she'd have a big pink bow on her head. Subverted in that Tiny's mother doesn't have breasts, either.
Theme Naming: Ben Ten(nyson) isn't 10 anymore, but is back to having 10 aliens on the Omnitrix.
There also seems to be a pattern of "-en" names in the Tennyson family, much to the amusement of Kevin in "Max Out":
"Gwen and Ken? What are your parents' names, Sven and Jen? I'm talking to you, Ben!"
Which is ironic, because Kevin (Levin)'s first and last names rhyme and gets even more ridiculous when it turns out his middle name is Ethan, which Ben mockingly points out makes him "Kevin E. Levin"...
...which makes Kevin something of a hypocrite now that we know his father's name was Devin Levin. And may in the future name his son Evan.
The aliens' "English names" are pretty much based on their personalities and abilities:
Rath, a creature of blind rage is an Apopplexian.
Kevin, who has absorption powers, is called an Osmosian by Ragnarock.
This Billboard Needs Some Salt: In one episode, Charmcaster brings a Mr. Smoothie sign to life. Ben defeats it by turning into Upchuck and drinking it dry. For some reason, Charmcaster's spell made it actually full of smoothie.
Upchuck was also able to use that smoothie for nuclear loogies when he has to use inorganic matter, but a wizard/witch did it and none of their powers are like they used to be...
Token Evil Teammate: Perhaps in response to complaints about odd characterization, Kevin became this in season 3 - actually killing a villain, war profiteering, etc. He still didn't quite undergo Character Rerailment until Ultimate Alien, though.
Took a Level in Badass: Ben took a massive level in Badass between the end of the original series and "The Return Of Ben 10", where he stopped acting like a dumb jerk and started thinking through his actions before jumping in, even asking Gwen for advice because he knows she's smarter than him, something the old Ben would never do.
D'void in Voided, who was known as Dr. Animo in the original series.
And recently, Julie.
Took a Level in Dumbass: Ben in season 3, when the writers tried Pandering To The Fanbase in a failed attempt to make him more like his 10 years old self, and he started acting more narcissistic and cocky again. Partially justified in-universe in that saving the Universe went over his head, but it sticks far longer than it should.
Oddly, if Ben switches from one alien to another in mid-battle, he does not need to shout the new alien's name. It seems to happen only if he's going from Ben to an alien form.
Apparently, it applies to all Omnitrix aliens in the series, not just the Alien Force exclusives. In the Season 2 finale, after Azmuth unlocks the Omnitrix Master Control, Ben transforms into Cannonbolt, complete with Alien Force-style Transformation Sequence and shouting the name. When Gwen asks Ben about his choice, he replies "I was feeling nostalgic." Later, he turns into Upchuck to fight off DNAliens, and then Way Big to try and destroy the Highbreeds' Warp Gate... without calling the names of either of them.
It's also inconsistent whether it's automatic or if Ben does it himself. When he turns into Lodestar the first time, he does it even though he's never seen the guy before. When he tries for Waybig and gets Humongousaur, he starts "Waybi.." * looks* "Aw man... (* exasperated* ) Humongousaur."
This is further complicated by Brainstorm, who Ben transforms into for the first time by accidental transformation, and names him on the spot instead of having a name prepared.
This is overused to the point that if the Omnitrix aliens weren't capable of intelligent speech, one might mistake their self-proclamations as Pokémon Speak.
Then there is a scene in season 3 where Ben transforms into the dog-like alien that can only snarl and Gwen says its name out loud in a low voice. When the screen focuses on her, she still has her hands cupped to her mouth with Kevin looking at her and Gwen shrugging and saying "what?" back at him.
When in the Season 3/Series Finale, Vilgax finally obtains the Omnitrix, his transformed robot army does it much more like Pokémon Speak, chanting the name over and over.
Translator Microbes: Kevin states that it's pretty common alien tech. So common, apparently, that it's even built into Plumbers' badges.
It doesn't explain why Sixsix and Sevenseven can't be understood, though.
Maybe they're using hacked tech that prevents all but similarly hacked tech from recognizing the language. It would be useful for the mercenaries to speak in secret.
Tricking the Shapeshifter: A variant that includes letting a character become a shapeshifter so that he can be tricked. Ben lets Vilgax activate the Omnitrix so that he can have him turn into Goop and incapacitate him by removing the gravity-device that allows Goop to function.
Unfazed Everyman: Julie. She's pretty cool with her boyfriend being able to turn into a plethora of aliens, and has an empathic alien creature that can turn into a warship as a pet. No matter what happens around her, she never loses her composure.
Not just the Omnitrix; Ship, a blob-like symbiote spawned from a Galvanic Mechomorph(AKA the species 'Upgrade' was in the original series) , is capable of transforming into any device he's come in contact with, and in season 3, he spontaneously forms a suit of techno-armor to protect Julie and fight off a pair of bounty hunters.
In the Alien Swarm movie, Kevin and Gwen pull up a map on the Plumbers base computer. It zooms in to an area in the upper Midwest, near the Wisconsin-Minnesota area.
White and Grey Morality: for the first two seasons at least; in those seasons, most characters fought by the protagonists were at worst Anti-Villains, at best misunderstood characters; even the Hightbreeds, despite being basically Nazi in space, turns out to be redeemable. Season 3, on the other hand, does give more actually evil characters.
Xanatos Gambit: Ben in the series finale. After Vilgax successfully steals and activates the Omnitrix, Ben uses a voice command to set it for a 30 second self-destruct note (In the original series, it was charged for several days, which is why the explosion would wipe out the universe; 30 seconds would cause an explosion of a much smaller radius but still be deadly). Vilgax either removes the Omnitrix and allows Ben to reclaim it, or the Omnitrix is destroyed. Vilgax choses the second option and gets his arm blown up. He gets better.
You Are Grounded: When Ben's parents find out (five years after the fact) that their son does the "transform into aliens and be a superhero" thing, they freak and forbid him from Omnitrixing. Fortunately, they come to an understanding and allow him to save the world (As long as he's being honest).