NOTE: Final Bosses and Wake Up Call Bosses are not allowed unless they're overly difficult by their standards. Extra Mode bosses don't actually count as Bonus Bosses, but will only be allowed to count if they stand out even in there.
- Meta Knight has a tendency to be this regardless of what game he appears in. Between his lightning-fast movement, hard-to-dodge attacks (particularly his lightning tornado and Mach Tornado attacks), and generally good A.I. (including being able to block your attacks in some games), not to mention that several games force you to fight him as Sword Kirby (which has very limited range, forcing you to get up close). Kirby: Squeak Squad balances this out somewhat by making him the penultimate boss and making him vulnerable to being knocked backwards. In Kirby: Planet Robobot, he uses a different attack pattern entirely. In Kirby Star Allies, he splits into 4 during his second phase, each attacking at the same time.
- Contrary to his status as one of Nintendo's iconic Warm Up Bosses, Whispy Woods is a menace in Extra Mode. While his attack pattern is largely unchanged, the big difference is that most of his apples have been replaced by Gordos, which deal three damage out of a maximum of six health in this game.
- Kabula, who was a pushover in the regular game, but in Extra Mode became the most insane, random, frantic battle in the game. Beating Kabula on Hard was as much luck as anything else.
- Kracko Jr. in the Extra Mode. Lightning fast, with a completely different attack pattern that gave you next to no time to react. note
- King Dedede can become obnoxious in Extra Mode, with his attack pattern becoming much more erratic and untelegraphed, coupled with his astounding ten units of health, more than any other boss in the game.
- As far as mid-bosses go, Rolling Turtle (Phan Phan in the GBA remake) is the most likely to give you hell. He tends to move unpredictably, you have to wait for long periods of time for him to actually drop things for you to shoot at him if you happened to not bring your best Copy Ability with you, and it's very easy to get caught in his catch-and-throw attacks.
- Heavy Mole is an autoscrolling boss that keeps destroying the earth in front of it, meaning that you have to constantly adapt to the perpetually changing environment, while avoiding getting crushed by the scrolling walls or falling into a pit. Heavy Mole's missiles offer two copy abilities: Hammer, which brings the double-edged sword of tearing the dirt that forms the arena, and Sleep. That's right, you can get the Sleep ability in this fight which slows Kirby down, likely screwing you over. There are cosmetic differences between the two types of missiles, but they're somewhat subtle and hard to notice when you're rushing to defeat the boss.
- Mr. Shine & Mr. Bright are incredibly tough for a World 3 Boss. Not only are they a tag team, but they both try to attack Kirby simultaneously, and you can only harm the one that's out on the field; the one in the sky is invincible. It doesn't help that once the first guy is defeated, he stays in the sky and still actively participates throughout the rest of the fight.
- In terms of minibosses, Captain Stitch takes the cake. A miniboss that's normally invincible until it lowers its defenses? That kind of thing never happens anywhere else in the series; Captain Stitch is the only one that does that!
- A wide amount of the bosses and minibosses are pretty hard, but the most egregious example is Mr. Shine & Mr. Bright. Aside from re-using their techniques from Kirby's Adventure, they now add an eclipse attack that does massive damage, should Kirby not stand in the umbra (the little spotlight the boss creates). Considering this, they're even harder than they were before!
- Dark Matter, the true final boss of the game, is absurdly hard by series standards, for several reasons:
- You fight him using what is essentially a Captain Ersatz of the Sword ability from Kirby's Adventure. Since you can't hit it from afar, you either need to get up close to the boss to deal damage (and even then it's minimal) or pull a Legend of Zelda and deflect projectiles. Both methods are frustrating to pull off, and players can be reeling for days trying to hit the boss.
- It has incredible speed, and its attack pattern just seems erratic. In its second phase, it even has the ability to shoot lightning in four directions. It'll take quite a while before you realize how to dodge it.
- The second phase of the fight features Kirby and the boss descending towards Pop Star. Like in Kirby's Adventure, if you don't complete the battle quickly enough, the cute little puffball will burn up in the atmosphere and die, meaning it's a Time-Limit Boss.
- Dyna Blade as Wheelie. Dyna Blade's head is the only part of her body that takes damage and is usually toward the top of the screen, so you can imagine the difficulty an ability that works by traveling along the ground will have. Wheelie's safest and most consistent strategy is to jump to the top of the screen (and Wheelie isn't a very fast jumper) and drive into her head over and over to chip away at her health, a very time-consuming strategy that is pretty much guaranteed to kill the run's time.
- Fatty Whale. This boss's attack pattern is randomized slightly, making him pretty unpredictable, and his attacks are pretty hard to dodge as well! When he gets the palette swap in Milky Way Wishes, he gets even worse, using a few new attacks, including attacks where he jumps across the arena! He's actually much slower in Ultra compared to how he was in the original, but he's still a pain to take out even in that version.
- Battling him as either Wheelie or Burnin' Leo makes it a lot harder. There are very few ways to damage him without a big risk of damaging yourself in the process. Helper to Hero as Wheelie is very difficult in general, since his ability doesn't let him do anything except drive into his enemies, and many bosses are hard to hit with him, either without taking damage, or at all.
- Meta Knight as Bugzzy. The only way the Knight can be hit, discounting the aerial kick because he usually will jump out of the way of it, is to grab the stars he leaves behind after certain attacks. Problem is, these stars can be impossible to get unless you're in specific spots (as one of these attacks takes nearly the entire screen and can't be dashed through). The one upside there is is that the stars do a good amount of damage, so you won't need that much to beat him. Again, good luck getting them in the first place.
- Galacta Knight is easy when fighting him with Meta Knight, due to Meta Knight's healing move, Mach Tornado, and powerful moveset. Then comes the fight with Galacta Knight right next to the True Final Boss with Kirby in The True Arena, and suddenly, he doesn't seem like such a wimp anymore. The player probably has low health by the fight, has to conserve health for the next boss, and cannot heal or abuse a super move like the Tornado. Worst of all are Galacta's Mace Knights, who, unlike the other Mooks he summons, are constantly attacking with a long-ranged weapon that hurts a lot. He was so strong, he returned in Kirby's Return to Dream Land as one of the two Bonus Bosses. And then he returned again in Planet Robobot to reprise his role as the Final Boss of Meta Knightmare Returns.
- Adeleine, the boss of Cloudy Park. Not only is she a Sequential Boss, but each phase gets harder and harder as the battle progresses. The hardest phase of them all is when Adeleine summons replicas of Mr. Shine & Mr. Bright, who were already difficult enough in Kirby's Adventure and Kirby's Dream Land 2. Any veteran of those games would know exactly why the phase is such a challenge. As a result, it's quite satisfying to see Adeleine jump down from her pedestal, blindly charge forward, and get knocked out from a single attack, even Kirby's sliding kick (which doesn't even do Scratch Damage to other bosses).
- 0, the game's True Final Boss. To start things off, it's a Sequential Boss with three forms, two of which have an enormous amount of health:
- First it sends a large mass of Dark Matter to attack Kirby, recreating the final boss from Dream Land 2 minus the time limit and most of the difficulty (unlike the previous game, Kirby's 11th-Hour Superpower can actually fire projectiles; Dark Matter is also noticeably less aggressive and lacks his ramming and laser attacks from Dream Land 2).
- Once it shows up for real, things start to get tougher. Despite being a much bigger and easier target for Kirby to hit, its mass also gives it the same advantage since its charging attack gives Kirby very little room to dodge. On top of that, it moves quickly and its attacks are very fast and rapid compared to the boss before it.
- After reaching the final phase, 0 tears out its eye to attack Kirby with it. Though this form has the least amount of health, it's much faster than the past two forms, a much smaller target to hit, and is a Super-Persistent Predator to boot. This combination makes it difficult to stop and take aim at before it catches up with Kirby and damages him.
- Miracle Matter has seven forms representing the different abilities in the game, each of which can only be harmed by using an ability that matches it or by sucking up his projectiles and spitting them back at him when he uses the same ability as the projectiles you inhaled, and it must be done quickly before he changes back to his main form anything that doesn't match the ability Miracle Matter is using will have no effect. Speaking of no effect, his main multi-eyed dice form is completely invulnerable (thankfully, it's also completely immobile, so it can only hurt you if you jump into it). All seven of his ability forms have to take at least three hits from their projectiles in order to be destroyed, and worse yet, you have to face all seven, which easily makes this boss battle one of the longest and toughest in the game. Since it provides you with abilities, you can turn into a fridge and give yourself health, but in Boss Rush, this is disabled!
- Mega Titan is a flying robotic suit of armor at least four times bigger than Kirby, with four detached (also flying) metal hands that are the size of Kirby himself. It attacks by using its hands to hound Kirby and his friends around the room, which is already tight for space with Mega Titan's size. You cannot stop the hands, and they will relentlessly pound you from every direction, sometimes all four at the same time.
The only way you can get the Mega Titan to take damage is by knocking its main body into the electrified walls on the sides of the room, four times to KO, or using Beam or Spark and that's easier said than done. Normal attacks barely move it back, and the Mega Titan's body tends to hang around the center of the room, meaning it takes 2-3 normal strength hits to get it into the wall; and during that time, you've probably been ganged-up on by the Titan's hands and taken some damage.
To add to the grief, this is the only boss in the game aside from the Final Boss that has more than one phase: Titan Head. This can thankfully be damaged normally, and two hits make it history. However, Titan Head is smaller and moves in an erratic zigzag pattern around Kirby who is probably low on health by now firing missiles and trying to ram into the poor little spud.
- Kracko doesn't appear in this game. Instead, you fight Mecha Kracko. While he's annoying enough on his own, once he Turns Red, he starts using an attack where he moves towards the bottom of the screen, destroys the stage, and reforms it later. If you don't take to the air in time, you will lose from falling off the screen. Regular Kracko may be annoying, but at least he doesn't use an attack that can cause a One-Hit KO at regular intervals. This is the only boss in the game that has two health bars to drain, even including the Final Boss.
- Bohboh is incredibly annoying to fight without either Hi-Jump or Tornado. The fight has a lava floor which is easy take damage from. Bohboh himself is very difficult to dodge. His grab attack also will cause you to lose your ability most of the time. note
- Dark Daroach. Teleporting around the room? Check. Long-lasting projectile attack? Check. Hard-to-dodge ice beam? Check. Bomb that sends a column of fire upward and covers the floor? Check. Plus, if you want Tornado, you'll have to get it beforehand. The game doesn't give it to you.
- Fatty Puffer is no pushover. He will inflate himself like a balloon (which makes him take up half the vertical area of the arena) and roll all over the place, shoot giant water beams, start jumping across the floor and ceiling, and spawn smaller enemies. And when he Turns Red, he gets even bigger, to the point where there's a small area at the top of the screen that he won't reach when rolling. Fatty Puffer EX is worse, as he will inflate himself to be even bigger, start rolling up the walls to reach you, can angle his water beam, and can shoot water balls when on the ceiling.
- Goriath. He wall clings just above the range of a lot of vertical attacks, forcing you to jump to get to him and sometimes he'll decide he's going to drop down on top of you, so if you're jumping under him and/or the floor is icy, he will hit you. If you're in the air when he jumps from one side to the other, he will jump right into you. When the floor breaks and gets icy in his second phase, it becomes easier to avoid his Ki Attacks and giant punches, but harder to get away from his body slam, that flying tackle, and the exploding spiky ice balls. He's so fast and jumps around so much that he's hard to hit. For Galacta Knight, and most other hard bosses in the game, dash attacks with invincibility frames are very effective but Goriath's floor changing and wall clinging make them useless at best, so you'd better get used to fighting a different way. Goriath EX, once he Turns Red, even gets a Spirit Bomb attack.
- Take Kracko, replace his electric powers with fire, make him gigantic, give him the capability to hide in the ground to grab you, rocket across the screen, and shoot large flaming blobs, and then give him a second phase where he's invincible, and you've got the Grand Doomer. On Extra Mode, he's even faster, will swoop so low you have to duck to dodge it, shoots screen-filling blobs that will explode if not destroyed first, has an even larger floor-hiding radius and faster speed, and overall more ridiculousness.
- Metal General EX may not seem that hard at first, but after you appear to defeat him, he summons HR-D3. Its attacks are quick and powerful, and can only be attacked at crucial moments. It can send a wave of missiles from one side of the screen to the other. After you think you've defeated it, it has yet another health bar, and flies onto the screen to attack you. It takes up about one-third of a screen, can shoot a large laser that rivals those of the Final Boss, and will sometimes spin around to attack you.
If you fail, you have to start a good chunk of the battle all over again. Since the player's max health is greatly reduced in Extra Mode, it can be a rather intimidating task. At least in the True Arena the fights are separated, and you have a longer health bar.
- The game's Final Boss, Magolor, is no pushover. He has a ton of attacks, ranging from shooting purple orbs at you to summoning enemies to a black hole. When you get his health low enough, he will pull up a shield that can only be broken with the Super Abilities. After defeating him, he will gain a second health bar and use stronger versions of the above attacks. He even uses the Super Abilities against you! And that isn't even getting into his Soul form in the True Arena... Good luck without an ability.
- Blocky, a Mini-Boss from the game, can be hard as a rock even in his normal form. It doesn't help that you will probably end up fighting his DX Form first. Blocky DX will normally turn invincible many moments and turn into a giant rock and crush you. He even returns in Planet Robobot, where he's as hard as ever.
- Kracko is an extremely difficult and annoying boss, especially during the second phase of his fight when you have to deal with Kracko raining lightning, launching a giant electric ball, launching dozens of electric balls, and charging at you with electrified spikes.
- Pyribbit refuses to stand in one spot for a very long period of time, and he will hop into the background when he feels like it, because that's where he's safe from your attacks. This means you have to give him everything you've got while you have the chance, while at the same time avoiding some of the devastating and oftentimes hard-to-dodge attacks he throws at you (notably his tongue and his exploding fireballs). He returns in "Team Kirby Clash" too, though at least his boss description sheds some light on his annoyance."A giant flaming frog?! Quick! Spank it silly before it hops back into the volcano!"
- Masked Dedede's Revenge is one of the hardest bosses in the game, as some of his attacks seem to home in on you. Fortunately, when revisiting the stage after beating the game, it gives you the option of fighting him or going straight to the Final Boss. Shadow Dedede from Dededetour is the same, but faster, more damaging, more random and inconsistent, and half his attacks cause unnecessarily large explosions.
- Dark Meta Knight's Revenge is a very difficult fight. Imagine Meta Knight, plus giant swords coming out of the ground, plus self-duplication, plus throwing tornadoes at you, plus King Dedede's slow speed.
- Remember Dubior from Return to Dream Land? Well, in this game, it's back and tougher than ever. Similarly to Blocky from the previous game, you're also more likely to encounter Dubior 2.0 first before encountering its normal counterpart (Dubior 2.0 is in the EX stage of the second world, while Dubior itself starts to appear in World 4). Add everything difficult about Dubior (unpredictable movement patterns, barriers, teleport spam, and more) and add the fact it constantly teleports to the screen and background (meaning that you'll be unable to hit it)... while sending out Dubior Jr.s at you. Unlike other bosses that attack from far away, you can't reflect the Dubior Jr.s with Mirror.
- In World 5 (Rhythm Route), the boss is a Dedede Clone. It supposedly behaves like Dedede... attack pattern and everything. However, once you deal enough damage to it, the next phase of the battle becomes a huge pain in the ass. It'll end up splitting into three smaller clones, which are all extremely unpredictable and difficult to attack. They will trip, hammer, jump, and even fly to get in your way. If you don't have a power that has an invulnerability period while dashing (Hammer and ESP are two examples), good luck, as you're better off without a power otherwise. That's not even the entire boss battle, as once you defeat the clones, they ride on a giant cannon and attack you from there. Fortunately, the boss becomes easier from that point on, as their attack pattern there is now slower and more predictable.
- The final boss in the True Arena in this game is extremely tough compared to the standards of other final bosses. Marx Soul only had one form, Magolor EX and Magolor Soul were fought separately (you could rest in between), and Soul of Sectonia had two forms you had to endure through. However, in this one, you have to fight Star Dream Soul OS and endure four entire forms. Because of how the True Arena works in this game (you only get recovery items after each fight, not a set amount like the previous ones), you'll most likely end up with low health after taking out Galacta Knight, the penultimate boss and probably one of the hardest bosses in the game.
- The first form enjoys spamming projectiles. If you haven't mastered the dodging technique, you'll most likely get damaged. It has new attacks, ranging from turning into a fireball and ramming towards you, summoning a bunch of meteors (which it has done before) and combining it with a deadly laser you have to dodge, and forming a barrier (that can only be destroyed by destroying the two small hearts it has)... while summoning giant Code Cubes and massive beams.
- The second form is a lot larger, but it has attacks that are far harder to dodge. The first thing it does is swallow a bunch of meteors (along with you) and spits them out. It also summons Gigavolts and missiles (which you can collect for the Planet Buster), but unless you're aware that the Barrel Roll can destroy enemies behind the Halberd, you'll probably get damaged trying to reach them. Additionally, its limbs have an additional attack where they'll fill up the screen, and can only be dodged if you're Barrel Rolling or at a particular corner at a particular time.
- Instead of a black hole-like move (which the second form uses instead), the third form starts off with eye lasers that will always flow from the top and go to the bottom (you can hit it while it's doing that). It still has the countdown move (meaning that if you don't beat the boss in time and don't time the dodge correctly, kiss your True Arena run goodbye). To survive the battle, you have to stay fully focused and keep hitting it at every opportunity you have. If you can destroy the objects it throws out, you can get fully charged Planet Busters, but it summons more obstacles than its first battle, which leaves you little time and room for error.
- Numbers 5-1. While 5, 4, and 3 aren't very difficult to avoid, 2 and 1 are. The former will quickly spin around the screen, and if you want to avoid it, you'll have to move around a lot and be very careful. The latter (assuming you haven't gotten to the fourth form yet) will spin around and charge at you at an unpredictable angle, meaning that you'll have to have good reflexes if you plan to dodge it. And if the battle drags on longer than that, well...
- If you were lucky enough to endure through three of these forms, you'll be fighting the final form. Thankfully, it fights more like a traditional Kirby boss battle... but the entire battle takes place in a circular field. The first phase is slightly easier (as a Call-Back to the Heart of NOVA battle), but the second phase is where things go to hell. It has very unpredictable Teleport Spam (you will have no idea where it'll go), it has several devastating attacks from lasers that will fire out explosions afterwards, cutters that are far more devastating and fire quickly, and a split-in-two attack that always follows with a massive explosion.
Sure, this battle may not be too hard if you're at full health, but this is after enduring three previous hard-to-dodge forms... meaning you'll have barely any health left unless if you managed to perfect run all of them. And unless your health bar is completely full (which is very doubtful), the very last few attacks it does are all a One-Hit KO that bypass every single semi-invulnerable moves (Stone, Archer, and Leaf, for example) except for ESP's teleport and the frames where Kirby gets an ability. If you aren't aware of that, you could potentially waste about thirty minutes for nothing.
- Later fights with Kibble Blade ("Tough" and "Tougher") rank among the hardest of the mid-boss encounters in the game. Kibble Blade is much better at protecting its front than most mid-bosses; its cutters are large, slow, and sweeping, so AI fighters get hit by them easily. Making this worse is that Kibble Blade doesn't move around much except when it charges, so it's hard to find a safe attacking position. When it Turns Red, it gains a nasty attack when it weaves in and out of the arena while spinning around a cutter; this is easy to avoid for human players, but the AI is easily overwhelmed by the large range it has. The AI struggles more against Kibble Blade than any other mid-boss, making it that much harder to reduce its HP within the time limit.
- And then there's the Greater Doomer. He shares all the attacks of his fellow Sphere and Grand Doomers, but he flies around so much that he's hard to land a hit on, compared to the preceding bosses moving at a reasonable enough pace for you to get them. This manages to be both annoying for the heavyweight Hammer Lord, who can pack a punch but can't run very fast, and the Sword Hero, who can run fast but can't land very many hits. And of course, gotta have that time limit. Hope you brought plenty of Gem Apples!
- Pyribbit is listed for Triple Deluxe already, but he deserves special mention here. He's the third Ordeal boss, roughly at the halfway point of the game. His love of stalling is carried over, but he's now got much more HP and attack, and a three-minute time limit to beat him in. In Team Kirby Clash, he's fairly beatable provided you grind a bit, but in this game, grinding is much more difficult and has less effect than buying expensive equipment. Mix this in with allies that are bad at dodging and you've got a very slow fight (in a game the requires fast fights), often marking the point where players either stop to grind Gem Apples or just start buying them. One more thing: to unlock the final area, you have to fight him again, and he's even stronger.
- Vividria is the only new mid-boss of this game, and undoubtedly the strongest of the lot. She has a wider variety of attacks than the rest of them, from raining paint to drawing up various projectiles, and she can even summon an animate sculpture to assist her. She's not too bad in Story Mode, but higher difficulties of The Ultimate Choice pit you against two of her upgraded form at once, which can form an early roadblock for solo runs (especially since they each have different attack patterns). Vividria's really making good on her promise to her sistersnote that she would do her best.
- Hyness can quickly catch players off guard due to the Difficulty Spike from phase one to phase two of his fight. The first phase can actually be considered a Breather Boss due to how easy his attacks are to dodge and how easily his health drops. But after his first health bar is depleted, he ramps it Up to Eleven. After he refills his energy, he starts attacking at a rapid rate, using attacks that can cover most of the ground, shielding himself while he throws attacks from behind. He will even roll around when his health reaches a certain point, making him both hard to dodge and hard to attack for quite a while. Corrupt Hyness, fought at the end of Heroes in Another Dimension, hurls more powerful and screen-filling versions of regular Hyness' attacks. And if you best him, well, see the Three Mage-Sisters below.
- The True Final Boss, Void Soul, takes an extreme difficulty spike from his standard form. First off, this form releases more shockwaves at slightly trickier patterns, making it hard to jump over. The effects of his blade attacks are also larger and harder to dodge. The second phase is more or less a Breather Boss, and the third phase abuses some rather nasty beam spam near the end. However, once you reach the actual Soul form, things REALLY get tricky. He opens with an unfriending wave which will force you to either stop fighting to dodge your own allies and try to either refriend them or defeat them. The boss splits himself into four large segments and bounces around the room erratically, flattening anyone it lands on. Eventually, it begins rapidly spamming some highly damaging beam attacks which require fast reflexes to avoid.
- You thought Void Soul was hard? Go to Soul Melter EX and say hello to Void. The first phase and third phase have air shockwaves, meaning you have to be careful with your jumps. In addition, the third phase gains MORE Master Crowns, going up to four, meaning more laser beams, even ones that require you to move in the other direction or take damage. And the spears it throws onto the battlefield? They now send out more shockwaves, causing everything to get hectic. And after you beat the third phase, Void reveals itself, pulling out a DonPachi-level Bullet Hell followed by even more laser beams than ever. If you are on low health when you reach this point (and you will be), say goodnight. Although it no longer has unfriending waves to turn your teammates against you (thank goodness) it doesn't make this part of the fight easier, what with the upgraded attacks and all. Although the horrid electrified water doesn't return, it does slow you down. In addition, it gains moves from the final bosses of years past: Dark Mind's laser beam/reflecting mirror combo; Drawcia Souls strategy of approaching from different directions and Zero's continuous projectile barrages. Once you reach the point where it Turns Red and solely uses the above three attacks, good luck. If you somehow endure all of that and tear Void apart, you unlock the ability to give Kirby his classic look from the main menu.
- Sure, the Three Mage-Sisters are complete pushovers for experienced players, but their fight in Heroes in Another Dimension has them get even more serious. Its you against three at the same exact time, and their moves can be tricky to avoid. But once they enter the second phase, things become rather hard. Its possible to become hit rapidly in a combo of attacks. And if you have multiple Dream Friends, good luck finding where you are, because thats going to be a challenge with these attacks going on, especially when you along with your Dream Friends also happen to be the Mage-Sisters themselves. During all of this, the framerate can sometimes lag, making things even more tougher. And whats more, to get the Happy Ending, you must beat this boss with 100 Friend Hearts collected, and if you dont have 100 Friend Hearts, time to go back to previous levels to get the Friend Heart count to 100 and then fight them again.
- Almost forgot about Morpho Knight, didn't we? What a joke he was. Not so with his upgraded version, Morpho Knight EX. Instead of standing around letting you attack him, he's the one on the attack, not stopping until either you or he go down. Furthermore, his laughably slow attacks are upgraded to the point where it's near impossible for any AI-controlled teammates to dodge. Oh, and in Soul Melter EX, he comes between the aforementioned Mage-Sisters and Void. Let's just say your death is pretty much assured.