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.
Kirby is quite a cocky Jerkass in Kirby's Avalanche (even though the game is not technically canon).
More famously: Kirby is a much less straightforward hero than most of them, notably eating definitely sentient beings alive, releasing eldritch abominations on a daily basis, and sometimes, going on quests and slaughtering people for rather... ambiguous reasons (in Squeak Squad: CAKE.) This led to many alternative interpretations of Kirby.
Brawl in the Family plays with this; for instance, Meta Knight once says to Dedede: "Like it or not, you and Kirby aren't that different, but where he has childlike optimism, you have untempered malice."
Sonic For Hire plays this as well in this episode. He then becomes somewhat of a regular character throughout the series, doing psychotic things like randomly eating people for fun and setting a bar on fire.
Dedede has a LOT more friends than Kirby in the games. Kirby's only in-game friends outside of Kirby 64 and the latter two Dream Land games are all created by him somehow. Everybody else has tried to kill him at least once.
The whole "storm the castle while your enemies panic" bit is repeated in the final level of "Revenge of the King" in Super Star Ultra.
Meta Knight wishes to have released the strongest warrior in the galaxy, locked away for fear of his power, for the sole purpose of kicking said warrior's ass. Which he proceeds to do note Or not, since this boss fight, while not Nintendo Hard, is pretty painful the first few times, because Galacta Knight is a computer controlled, white, and feather-winged, extra-badass Meta Knight with a lance and shield, making the fight as fun as it is awesome). Why? For training purposes. Or fun. Or just to prove he could.
Cult Classic: Air Ride has been getting more and more popular each year since its release thanks to its sandbox-like City Trial mode. Helps that it was the last Kirby game that Kirby's creator Masahiro Sakurai worked on before leaving HAL Laboratory to start his own company.
Designated Villain: Many games have Kirby attack King Dedede and his forces under the assumption that he's the villain, when in fact Dedede turns out to be trying to STOP the real villain of the game.
Draco in Leather Pants: Many Kirby fans think Zero is a lonely, sad being that just wants some friends - though this does have some basis in canon, as it's stated that Dark Matter can't feel positive emotions and wants to destroy the world out of jealousy. The awesome battle music probably helps (especially the Zero 2 music mentioned above.)
Even Better Sequel: The original Kirby game was a fairly standard side-scroller that was pretty enjoyable for what it was, but was laughably short and easy (although the latter is compensated by the unlockable Hard Mode—and it lives up to its name, all right) and didn't even allow you to copy abilities! Kirby's Adventure then came out on the NES and blew the original out of the water by offering more levels, the series-trademark copy abilities, and a save feature! Kirby's Dreamland 2, while not quite as good as Adventure, at least brought these improvements down to a portable level.
One Japanese guidebook for Kirby's Dream Land 2 claimed Dark Matter was a Tortured Monster that attacked Popstar because it was jealous of all the "happiness" there. Just about every fan accepts this as official canon, but they alwaysflanderizeit into applying to 0/02 alone, despite him not being introduced until the sequel (The Tears of Blood likely have something to do with it).
Did Bandana Waddle Dee appear in Kirby 64, minus the blue bandana? Some fans think so.
Fridge Brilliance: Why are the Big Bads of the games usually so nightmarish? Because it's Dreamland, it's only fitting that the antagonists inspire nightmares.
You can destroy The Arena (and later The TrueArena) with Hammer and Plasma, the former having Hammer Flip, which does one of the highest damages of a non one-time-use ability in the game, and the latter of which provides an extra shield when fully charged.
If you master the quick charge trick, the aforementioned Plasma power from Kirby Super Star becomes the most broken power the series has ever seen. Due to this, it was slightly Nerfed in the DS version, requiring more charge-up time.
There's also Tornado, which has the amazing ability to kill almost every boss in the series. In fact, every boss in Squeak Squad can be killed very easily with it, including the final boss. It's an even better choice for the final boss than the Eleventh Hour Superpower! Cranked Up to Eleven in Kirby's Return to Dream Land, where stronger moves were made avaliable. You can annihilate Magolor Soul pretty easily with Tornado. Yep, an Infinity–1 Sword in comparison to Super Abilities.
Also Hi-Jump, at least in Kirby's Adventure, which not only does high damage to bosses, but makes you invincible while doing so and sending you out of harm's way. Not always useful outside bosses, however.
The Copy helper (TAC) in the original Kirby Super Star on the SNES. Normally, it allows the helper to copy abilities like Kirby himself. But if there's no power to copy (mostly on bosses), it just does massive damage! And it's spammable! See for yourself, especially 2:52. It completely heals every time you copy a power, and when it guards, you become immune to all damage as well.
In Dreamland 2, Coo + Parasol can rip apart everything including the angry Propeller Bombs. The whole thing got a well deserved nerf in 3.
Chu Chu's Clean power trivializes any midair segment (short of those that require quick movement).
The music for Ripple Star's second level. The cute Sugar Bowl of the first level is quickly cut off when you reach the second and are welcomed with the ruined fairy castle and hear that damn Scare Chord dirge.
Rick the Hamster. With the Stone ability, he can roll.
"Mago" means "wizard" in some languages, and "lor" means "dirty" in others (and he does fit the name of Dirty Wizard). This would be a Meaningful Name if the two meanings came from the same language, but since they don't, it's just a funny coincidence.
It's Easy, So ItSucks: The games may be easy, but this is generally averted - they were actually designed to be very easy yet nobody seems to have any problem. This becomes quite weird when you hear this trope being invoked elsewhere, since how many other games allow you to fly over most of the stage without even having to find a power-up?
Love It or Hate It: You'll either love the slower paced gameplay, Gooey, Animal Friends and scribbly graphics of Dream Land 3 or hate it for just the same reasons. The most hardcore of the fanbase generally like it, though.
Marx, who arranged for the sun and moon to fight and used Kirby to summon Nova so he could wish to take over Popstar.
Yin-Yarn lands himself right in this spot since he demonstrates his plan to take over Dreamland by having his fake Waddle Dees capture the real ones and then capturing and brainwashing Dedede and Meta Knight and sending them to Patch Land to fight Kirby under his control so he can have Dreamland all to himself. And, unlike most other villains, Yin-Yarn actually succeeds in taking over Dreamland.
Magolor, you magnificent bastard, we read your BOOK!
And now we have our newest one; Queen Sectonia, who saw through the Floralia residents' plan to bring the hero of Dreamland to their rescue and sent Taranza to kidnap him in order to keep him from interfering with her gambit to rule Popstar as its goddess, even though she didn't count on him kidnapping Dedede instead of Kirby like she wanted him to.
During the Boss Rush in Super Star, you will have to fight a Waddle Dee with five times the health of a normal Waddle Dee. It's still a Curb-Stomp BattleBreather Boss (he doesn't move, and you can still inhale him.) A video on the internet portrayed him as an unstoppable god of destruction (via a player who thought it would be hilarious) and the fandom's pumped him up ever since.
In case anyone wants to argue, here is Waddle Dee proving his point. Contains spoilers!
Kirby himself is this. There are Nintendo fans who firmly believe the pink puff's badassery is only rivaled by Captain Falcon.
There was also a YouTube fad involving Dedede screaming random things after getting beaten at the end of Spring Breeze.
INVINCIBLE CANDY! (A running gag on Something Awful Let's Play of any Kirby game, second only to...)
DELICIOUS! (Whenever any food item is eaten, but especially Maximum Tomatoes.)
The "Kirby ASCII Dance": (> ")> <(" <) (^ ")^ (v ")v
Kirby's Epic Yarn brings us Kirby's arrival in Patch Land and his observation that the grass feels like... pants.
Rick's Stone ability in Dream Land 3 has been dubbed the "Rickroll".
The title screen music of Kirby's Pinball Land has become synonymous with a well-known copypasta where an Anon walked in on his parents having sex while the music was playing on his Gameboy.
Never Live It Down: In Kirby Squeak Squad, Kirby went on a rampage over a piece of cake. In every other platform game, his goals are more noble, although some fans hang on to this one instance and insist Kirby is a Sociopathic Hero.
Periphery Demographic: Though the games are and remain mostly geared for children just beginning to play video games, a good chunk of the fanbase are experienced gamers who grew up playing them and who gleefully return to each new installment, no matter how short or easy it is.
In Super Star (and a few other games with co-op) A player can share the effects of a recently consumed food item by walking up to their ally at which point the two get face to face for a second. There's really no other way to interpret this animation as anything but player 1 spitting up what they had just eaten into player 2's mouth...
Or they share the health gain with a kiss. There's a distinct smacking sound when you do it.
Tear Jerker: The ending of Revenge of the King in Super Star Ultra. Poor Dedede. See here for more.
They Changed It, Now It Sucks: Nightmare in Dream Land is markedly easier than the game it's a remake of, Kirby's Adventure... and it removed the rotating tower segments from Butter Building for no apparent reason. Fans were not pleased.
Viewer Gender Confusion: Kirby's gender is actually a mystery in the Japanese games, and the original developers refuse to designate an official gender. Averted in most translations since gender-neutral pronouns don't always work out (especially in English, which usually defaults to the masculine form).
Invincible Villain: Nightmare seems like this at first. In the games, his cape protects his tornado-like body, which is his weak spot. In the anime, he uses his cape to absorb attacks. He even treated the final battle as a joke and a fun game until he saw Kirbyeat his own Warp Star and become Star Rod Kirby and use it to destroy him. To be fair, he lives up to his name since he's a living nightmare and therefore can only be beaten inside a dream.
Vindicated by History: At the time of its release, Dream Land 3 wasn't received very well because players wanted a game similar to Super Star, with copy abilities that had multiple moves and was fast paced. Dream Land 3 returned to the slower paced style of gameplay of Dream Land 2 and brought back the Animal Friends. It also had a very controversial art style, using crayon and colored pencil-like graphics, something never before seen for a game in the series. In the present, it's generally agreed Dream Land 3 was a very good game, if not as good as Kirby 64: The Crystal Shards or Super Star.
It didn't help that Dream Land 3 was one of the very last games for the SNES, coming out over a year after the Nintendo 64. It's actually amazing that HAL averted No Export for You for it.