The Core(in the Labyrinth) in Cave Story, which not only fires more bullets than the final boss(Undead Core, which is actually the same core, but possessed by the Doctor), and only allows you to fire on it in specifically defined places, but periodically fills the room with water, not only forcing you to immediately rush away from the boss, often during the short windows in which it is vulnerable, but restricting your movement and making it much harder to actually dodge the projectiles.
Made worse by the smaller Corelings that circle the bigger one. You can shoot them to stun them temporarily, but the only part that takes damage is the main Core, and only when its eyes are open, which only lasts for a few seconds. The problem is that the Corelings tend to get in the way of your bullets. If you're using Blade lvl 3, one Coreling in the wrong place can really screw you over.
Then there's Hard Mode. 3 HP (8 in 3D). No missiles. You cannot get hit by any of the Core's attacks at all and your stronggest offense is gone. Unlike other bosses, the Core likes keeping a certain distance to your right, meaning you can't use a defensive strategy. The fight becomes a Luck-Based Mission based on which Corelings become active and how many of the bullets you can destroy and/or dodge while damaging the Core.
Monster X, found a few levels prior to The Core, can also be That One Boss. It shares The Core's invulnerability except at specific times, and floods you with bullets, or in its second stage homing missiles, when it is vulnerable. It also forces the player to ride on it or be run over, and you risk being smashed into the walls of the room.
Toroko is worse than Monster X - her attacks can be dodged, but doing so is often difficult, and Mooks also spawn, which seem not to be much of a threat, until you end up having to kill them while dodging the main attacks. Did we mention that each time you are hit, you will likely lose a level from your weapon? In addition, you have to be very careful with your health as afterwards, you will have to go quite a way for a save point or any decent amount of health refill. At least you have the Blade when you fight Monster X, which wrecks it really quickly at level 2. You can only take TWO OR THREE hits before you DIE! The Machine Gun helps, but only at level 3 or until it runs out of ammo, and if you're trying to get the Spur, you cannot have the Machine Gun. And this is something that was once a cute little bunny.
Custom Robo Arena. For the most part, the battles are moderately challenging, and the rules are clearly defined. The last four 'face' opponents according to the plot are slightly harder, mostly due to being cheaters, but nothing overly major(Snipe is fast but fragile, and his magma stage can hurt him too, ViolentBoar is strong but slow, Freya and Katana both have stages that hamper their effectiveness as well). But then, between the first set and the second set of the above, comes Jameson, the final Gate Keeper. The problem with Jameson is that he doesn't act like a proper robo, instead fighting more like a vehicle: it doesn't flinch when hit, it doesn't go down, and it plays keep-away in order to shoot you dead. And it's VERY good at shooting you dead. Odds are good you'll have to adopt a radically diffrent strategy to fight it. Even worse if you used Soulboost, as after fighting and subduing the big robo, you get to fight a second (slightly easier)one.
From the Gamecube game, recurring boss Rahu will make you weep whenever you see him appear. He deals enough damage to kill you in three or four hits, whereas his defenses will make you play a game you cannot win. He's so bad that the final battle is a three versus one battle with you, Harry, and Marcia versus Rahu, and you're either coming out of it with you being the last one standing, or everyone is going to be down to their last 100 health if that.
In the SNES game Illusion of Gaia, the debates rages about which is worse: the first boss, or the married vampires.
The spiritial successor to Illusion of Gaia, Terranigma, has Bloody Mary. Unless you're several levels higher than you're supposed to be at that point in the game, your weapons only deal around 1-4 points of damage to her and she needs hundreds of attacks to go down. That said, she is quite vulnerable to magic. Which would make things easier if it wasn't for the fact that she is the only boss in the game you can use magic against at all.
Baron Praxis is genuinely extremely hard in Jak II (even for Jak II, which was a hard game). What makes things worse is that he's the first boss you fight.
Koudelka runs into this a lot, due to its less-than-admirable combat system. One particular example will suffice: Alias, a gunman who ambushes you on a staircase. He runs back and forth between two boxes, shooting at you and usually dealing enough damage to kill whoever he hits. But you can't reach him with a melee attack until you destroy the boxes, and he's somehow immune to magic, meaning he'll continually pick you off as you work on destroying the boxes...
Every boss in La-Mulana not named Amphisbaena has been accused of this, but most are actually reasonable with the right sub-weapon. The only two serious candidates are Sakit and Tiamat.
Sakit is the boss of the second field, and a big step up from the laughable Amphisbaena. He stomps back and forth on the screen, dropping rocks on you and stopping to either use a Rocket Punch or shoot magic at you. The only way to damage him is to run up his arm when he uses the rocket punch and attack his face. Hope you went into the Temple of the Sun and found the Knife, otherwise you're just going to be Cherry Tapping with the whip. Did we mention he's immune to all subweapons?
Tiamat is the boss of the Dimensional Corridor, the penultimate boss in the game. Unlike Sakit, you can't sequence break around her and come back overequipped; you fight Tiamat at full power, and she's a nightmare. She constantly generates bats, and attacks with her tail and her Prehensile Hair. She's also extraordinarily hard to hit with subweapons, so your Pistol shots that you ground for are probably going to go to waste unless you have incredible timing. If you have the Castlevania/Mahjong Wizard ROM combo and the Mace, it's a challenging fight; without those, it's murderous.
The remake changes things up a bit. Sakit retains his That One Boss status in this game and is only made worse because the knife is a far less reliable way to hit him this time around, but Tiamat is actually quite a bit easier due to having a far less irritating strategy tacked onto her, to the point where she's almost like a completely different boss fight. That said, Baphomet (who in the original was almost a Breather Boss) is more than happy to take Tiamat's place as That One Boss in the remake, as she goes from a sitting duck that waits for you to drop bombs on her to a nightmarish marathon of a boss fight consisting of two forms and a great many hard-to-avoid lightning bolts. She's considered by many to be the second hardest fight in the game, behind only the final boss itself.
Bomamba from NiGHTS: Journey of Dreams is a fight in which you have to tilt a board to get a bunch of cat heads into holes. Sounds easy enough, but the physics are utter rubbish and if the cat head twitches going into the hole it rolls straight over. And, on top of that, you can't pull the board towards you and have to constantly circle the board... by which point the cats have moved to another position and it starts anew.
The Chameleon, being that you can spend your first few tries before even finding out how to look for the thing. There's also the Cerberus.
TeaTea from stage 2 of Myifee's storyline in Ninety-Nine Nights is the living embodiment of the "bottleneck to make sure you levelled" version. If you try to go at him at level 2, he's essentially impossible to beat, your attacks just barely chipping at his health while he decimates you. If you take the time to kill everything and get up to level 3, your cool new sword and improved stats will make short work of him.
Silent Hill 2: The Twin Pyramid Heads, particularly on Hard difficulty.
Silent Hill 2 also has Eddie, partially due to being the only enemy in the game that uses a gun.
The God in Silent Hill 3, while fairly easy on Normal, becomes That One Boss on the Hard and Extreme. She has a ton more HP, requiring you to use your limited ammo and weapons strategically (melee attacking when her head is down during the first half), and once her HP is half depleted, her firewave attacks become much faster and deadlier. Prepare to die many times before figuring this out.
For many, Scarlet from Silent Hill: Homecoming also qualifies— not necessarily due to difficulty, but because numerous copies of the game have a bug that makes the fight Unwinnable.
As soon as you enter the frigid tundra that is Kamui, you are faced with a mysterious man in a mask... Oki. He's definitely the hardest boss fight in the main game, especially his attack where he shoots ice shards at you that is tricky to dodge (and if you're frozen, you're so vulnerable you can't even pause). And when you finally get his health down to zero, he goes One-Winged Angel by turning into a wolf! You've dealt with canine warriors before, but none of them can create copies of themselves that can tag-team, throw bigger ice shards at you, or hit you with a BFS! Also, while you can block said sword swings with a sub-reflector, even if you get the timing right you can't perform the Izuna Drop counter-attack on Oki... for some reason.
If you don't know the strategy then Ninetails also qualifies. Making him split into his nine smaller bodies isn't hard, but then you have to defeat each of those bodies themselves. If you get hit by them once, though, the other eight will come at you and combo attack you until they reform into Ninetails again without the slightest window for attack. Also, there's invincible flying skulls spitting orbs at you the whole time and any damage taken is healed upon reforming into Ninetails, so you can't do some and then pick up where you left off. Only if you start the assault with a glaive swing before they get close enough to hit you can you start comboing them and doing damage... not helped that on the Wii version glaive-charging is extremely unpredictable.
A perfect example of That One Boss was Mysterio from the first Playstation Spider-Man game. The method to beating Mysterio was straightforward and obvious enough, but the twitchy controls made shooting your webbing difficult at best, particularly while avoiding Mysterio's attacks. Hilariously subverted in the second game based on the movies. His health bar fills up... three times, and then you defeat him with one punch
Ultra Mega Mega Man, the final boss of the South Park FPS for the Nintendo 64 and PlayStation. Once you get its health down, it starts healing and it's very hard to stop it.
A note on mother bear: She's like the rabbit fromMonty Python and the Holy Grail...but a bear. She can kill most of your party members with one shot, and like most giant predators, she doesn't need to take much of a break in between killing children. If When Animals Attack were a game, it would be a lot like the mother bear fight.
Fighting the Emperor himself in Super Return of the Jedi. He spams Force Lightning ALL OVER THE PLACE, which destroys the walkways you're fighting on. It can get to the point where there's barely any flooring left to stand on and it's also possible to fall do your death AFTER killing the emperor!
Near the end of Fullmetal Alchemist: The Broken Angel, there was one of the most painful boss battles in the game. It consists of a revisit to the three chimera bosses you fought individually earlier in the game: the Behemoth, the Griffin, and the Serpent. Now by themselves, these guys weren't so bad, but fighting all three at once was beyond ridiculous. The Behemoth takes very little damage at a time and has the capability to heal itself, and also fires homing projectiles. The Griffin spends most of its time out of your reach, flying around above the arena and dropping a constant stream of fireballs. Meanwhile the Serpent enjoys playing a game of Lethal Whack-A-Mole with you as it randomly pops up from the pools of water situated around the arena and using a flurry of attacks to ensure that coming near it will take a large chunk off your health. It goes without saying that this fight is a living hell for the player.
Then there's Pride in Dual Sympathy. He's not too much trouble most of the time, but when you play as Roy...
In Curse of the Crimson Elixir, the second time you fight The Phantom/ Elma's "chimera" form. She never stays still and will more than happily dance around Ed's attacks then kick combo him in the head. She also takes little damage from attacks (even max level alchemy bombs} and at around half-health begins to summon several giant golems that fire projectiles all over the battlefield. Making it very easy for poor Ed to be juggled to death via Beam Spam.
Yaha and his gnomes from Drakengard 2. When there aren't a whole lot of noisy gnomes attacking Nowe en masse, the floor randomly lights up with circles that produce highly damaging stalagmites. And once that's over, there's the giant gnome/rock monster thing itself... with a tendency for overly powerful attacks, including one that is nearly impossible to dodge. Rinse and repeat until you kill it. Ugh.
Good luck beating the boss of Area 6 in Blaster Master without cheating. It's a palette-swap of Area 2's boss, but it has more Hit Points, projectile attacks in addition to its claws, and gives you very little room to maneuver.
The boss of Area 5 is a pain in the ass to beat, too. To make the long story short, those bubbles he shoots will block your shots, and he spews out more and more as you wear him down. It doesn't help that the grenade-pause trick doesn't work against him.
The third Owata clone in the The Life Ending Adventure. The first one is easy, the second one is pretty hard but the third one is almost unbeatable. The fact that he heals when he's low on HP and that you are the One-Hit-Point Wonder don't help at all. The whole game is obscenely hard, no wonder I Wanna Be the Guy was based on this.
Andross in Star Fox Adventures.It wouldn't be so bad if it weren't for the fact that the game up until that point is largely based on on-foot, Zelda-style action, and suddenly he takes the shooting segments from the starts of the levels and makes them the focal point of his fight.
One thing that makes this fight way worse than it should be is his sucking attack. It's nigh unavoidable, as opposed to the previous games in which it was an utter joke. You have to SPAM barrel rolls while boosting (you read that right, boosting, not braking) as much as possible in order to slow down juuust enough to not get sucked in. Normally this wouldn't be an issue. And it isn't... later in the fight. If he gets you with it while he's still in the first form, whichever hand you destroyed, if either at all, regenerates, so the whole first phase just resets. And unless you're SERIOUSLY skilled and can destroy both hands in one go, you're going to have to deal with this attack at least once.
Dynamite Headdy has a few tough bosses near the end, but Izayoi/Nasty Gatekeeper is That One Boss for two reasons: The traditional reason; she's hard. She has a lot of deadly moves and she uses them very fast. Every time you hit her, she strikes at you five times at hyper speed. It's nearly impossible to avoid if you don't know what you're doing, and still pretty tough if you do. Headcase (your source of powerups), when he is there, is spinning around wildly in the nasty gatekeepers grip. Most bosses, while perhaps on the hard side, can hardly begin to prepare you for this fight. So even if it's not the hardest, it definitely sticks out.
Hunting down and killing Pulaski in Grand Theft Auto: San Andreas. When you start the mission, the car you came in (assuming you came to the starting point by car) will usually have vanished. Pulaski drives a Buffalo, a very fast and durable sports car, while you're stuck with a weird looking off road car that handles like crap. To even get Pulaski to get out of his car, you have to wreck it by either making it flip over via ramming or pumping it full of lead with a drive-by. Even when Pulaski finally bails, he shoots you with a friggin' Desert Eagle, the most powerful handgun in the game which can knock you down. If he knocks you down with it, he'll keep shooting at you until you're dead. Oh, and his health is sky high, requiring a lot of firepower to take him down. Although it is possible to run him over or use explosives, usually your car is near a total wreck by then and Pulaski's gun can bring it to a near total explosion, forcing you to bail.
First is Mz. Ruby from Sly Cooper and the Thievius Raccoonus. She's just a musical rhytm minigame, however, you can only screw up a maximum of three times in about three minutes before having to start the whole fight.
The honor of being the hardest boss in the game belongs to Clockwerk, the final boss. His first form is simple enough; just circle to avoid the energy blasts, and shoot whichever part Carmelita electrifies. After he crashes into the lava, he rises like a phoenix and things get difficult. You have to shoot the electrified body parts as before, but this time he launches electric rings that zap you unless you place yourself perfectly in the middle. Maneuvering through the rings is frustrating enough, but even after you empty his lifebar for the second time, there's still a third stage, and it's the worst of the lot. Now you have to run across some rocks and debris over a field of lava, dodging vertical lighting blasts and rotating security lasers on your way to Clockwerk's crashed form. And the worst part? 1-3 hits (depending on how many horseshoes you picked up) and you have to start the fight over from the first phase.
And in case you were hoping you wouldn't have to deal with Clockwerk any more, the second game proves you wrong. The first phase is yet another aerial turret section, where he (er, actually Neyla fused with his body) constantly swoops around, and your shots don't do as much damage as they should. He spams missiles and can use an attack that can take off a third of your health in one shot unless you shoot him enough, and with his constant swooping, realize how tough it can be to deal with. Once you somehow get his health down, he brings out the electric rings, and you have to shoot them to not get zapped for heavy damage... and not shoot them again by accident, which turns them back on. But when you're about to take him down, you then have to deal with the most frustrating platforming sequence in the game in order to get to him again, and messing up starts that sequence all over.
Don Octavio, who is quite difficult for the first boss. Think an old guy like him would be slow and easy to take out? WRONG. You can't even hit him unless you flood the arena with tar; try to punch him when he's not in it and he counters by jumping on your head. You've also got to deal with his rushing flurries of punches and ground pounds as well. Even though Murray has a good deal of health, he'll easily chop it off. Even when slowed, most of the time punching him will knock him out of the tar, forcing you to chase and deal with his strong attacks. And in the second phase, he gets a pretty strong projectile attack to deal with as well. And if you lose? Back to the very beginning for you. But then there's the bonus mission where you have to defeat him under a very strict time limit. That's no fun.
The game also has the battle with General Tsao, a tough two-part battle. The first half is fought under some quite strange mechanics; jumping once causes you to soar without stopping, and double jumping changes your course. If it sounds easy, wait until you have to do tricky maneuvers to hit Tsao without hitting his spinning shield. He also shoots energy projectiles at you. Then comes the second half. You're on the ground, but things aren't much easier. Tsao will use his spinning shield to counter your attacks. He also can punch the ground to send waves of undead hands to chase you, which require you to climb the bamboo shoots to stop them... and guess what both of your attacks can easily destroy? He also shoots homing dragon heads, which cause a nasty Interface Screw and make it hard to see what's going on. If you don't have the Push Attack, it's a brutal fight. Oh, and if that wasn't enough, the Challenge version requires you to beat both phases (seperately) with only half your max HP.
The swordfighting duel with LeFwee. Until you learn how to fight, you will get stomped... and when you get the hang of it, it's still a monotonous 3-stage battle where losing forces you to start all over.
There's Grizz in the fourth game. He's invincible for most of the fight, and he skates around the arena while slamming you with a constant barrage of attacks that hurt. Shockwaves that freeze you, dashing into you at high speed ("HERE COMES THE GRIZZ"), sending icicles smashing into the floor, and sending out a spreading wave of ice blocks, he's got them all. All you can do is dodge his attacks until he starts a new attack, which takes forever on the third phase. Here he summons a circle of monoliths around him, and you have to punch ice blocks in the circle... but they take a lot of hits, and all this time you're being barraged by icicles (which actually have a blast radius) and shockwaves. Take too long and he shoots out the monoliths, doing lots of damage. When you do get them all? You're not done yet, as you have to go through a memory/rhythm minigame. It's easy at first, but then the inputs start being blanked out. Mess up just once on one of those and you have to go through the whole sequence again. And you have to do all this three times before he goes down. Your only saving grace is that checkpoints are after each time you deal damage. Oh, and he's at the end of a long stage. Have fun.
Starscream in the Transformers Armada video game. Even on the ground he's insanely fast when he's not walking straight at you. When he takes to the air and starts strafing it's hard enough to figure out what direction he's coming from, let alone actually landing a hit on him. With the right combination of Mini-Cons you can get the weaponry necessary to beat him without snapping your controller...which would be great if he wasn't the second boss of the game.
See also Cyclonus. The battle begins atop an ancient pyramid, and one of Cyclonus' first acts is an unblockable (and probably unavoidable) throw that usually sends you sailing off the pyramid For Massive Damage. He follows this up with a strafing attack that eats up your life, and seems to be unavoidable for everybody except Hot Shot, who can avoid the attack by transforming and hiding underwater.
In Prince of Persia: The Two Thrones, this overlaps with the Dual Boss. You fight two baddies, one who carries a sword and parries all attacks, and one who carries an axe and is too heavily armored to hurt. In order to damage them, you have to first attack Sword Guy ineffectively until Axe Guy leaps at you from behind. Dodge so the axe gets stuck in the ground, giving you a very short window to run around behind Axe Guy and hit him, once. Repeat this for many hits and eventually it will trigger an Action Commands scene that will let you do a small amount of actual damage to the bosses. Then do the whole repetitive thing over again, twice, to kill them. If you fail to dodge the axe, you take 50% damage and get knocked down. If you miss the timing on the runaround, Sword Guy will unblockably combo you to death. God help you if you screw up the Action Command. Oh, and did we mention the surrounding Ring of Fire that hurts you and not the enemies? And that this whole thing happens immediately after the chariot-racing Scrappy Level, without a save point in between? And the level isn't even over once you beat them. Yay.
Any boss battle with Shahdee in Prince of Persia: Warrior Within could be considered That One Boss, simply because if you didn't follow the strict pattern of the fight the game gave you to the tee, the boss would take half your life bar away in a flash.
Ultimate Spider-Man has quite a lot of these. The second fight against Venom and when you fight Electro is awfully hard. Green Goblin, who looks like the Hulk on fire, is hard considering you have to dodge fire balls and while doing that you'll sometime miss your chance to harm him. You then have to go into a flaming church to fight him and it's hard.
The hardest of all is Carnage. You play as Venom but he fights similar to you. When you beat him up enough he hides behind a gate that is very hard to move and then he goes into another one. He also fights hard and can heal again afterwards.
Another bad one is the fight against the Beetle as Venom. You're in a room that is filled with traps that can drastically take down Eddie's health, and the little bastard can quickly fly out of range from your attacks. To top it all off, this is the only boss fight Venom has where there aren't any random humans running around to eat and allow you to regain your health, and since Venom's health is always going down the entire game, it means that this fight essentially has you against the clock for the whole battle.
Speaking of Spider-Man, in the N64 Spider-Man game, Venom is ridiculously hard considering that he's only the second boss in the game. Walk too far away from him, and he pulls you in with an unblockable attack; Get too close to him, he grabs you with an unblockable attack. He has twice as much health as the player, and one of the only too meager health pick-ups is under a larger container which takes a few seconds to lift—meaning that if you try to grab it, he'll probably be able to attack you.
Another Ultimate Spider-Man example comes from the iPhone game Ultimate Spider-Man: Total Mayhem. Most of the game is a cakewalk, but only because it's practically refreshment following The Rhino, the very second boss. Most of the later bosses have the benefit of letting out health power ups every few punches, but with Rhino, there is no such mercy. You can expect a third of gameplay time going down the drain as you face three stages of relentless smackdown from the brute and his ridiculously powerful charges.
Spider-Man: Web of Shadows, the console version, brings us Electro. The fight comes not long after another tough boss, Venom, and the player is probably hoping for some nice breather missions afterwards, but instead, your friendly neighborhood electrocharged criminal crashes the party and starts spazzing out on everyone. Too much of the fight relies on you web-slinging and chasing Electro through the city; while web-slinging is fun when you don't have to be too precise with it, this fight reveals just how imperfect the mechanic is, especially because you lose and have to start over from the nearest checkpoint if he gets too far away. And you can't easily track him with your eyes or spider-sense, because he simply teleports from place to place. When you finally do get to fight him, prepare for a tough, confusing light-show that can easily camoflage attacks. Perhaps the worst part is that after all this, Spidey isn't even the one who gets to land the final blow.
Kakistos in Buffy The Vampire Slayer: Chaos Bleeds. You fight him in an cramped area where he is using three magical orbs to restore his health: you have to hit each orb three times (which means you have to go and hit each orb once, then hit each orb again, and then once more) to destroy them. While zombies come out of the ground and get in your way and attack you. And Kakistos hits you with fireballs and flaming oil bombs that chew right through your life bar, if he doesn't just kick you upside the head. And then when the orbs are destroyed, you still have to take him out. With zombies still coming. Strange how an old vampire is harder then the source of all evil.
Ys: The Oath in Felghana is for the most part a cut-and-dry PC reimagining of the third game in the series, Wanderers from Ys. However, one boss went from laughably easy to downright nightmarish in the transition from sidescrolling Action-RPG to top-down Zeldalike.
Death Faleon is UNQUESTIONABLY the hardest boss in the game, bar none, and it's especially ridiculous considering what a complete pushover he was in the original Ys III. Seriously, even when properly leveled (which you won't be), this guy is an complete nightmare. He's got more attacks than any other boss (and those same attacks track you with incredible accuracy), a shifting elemental weakness, he moves extremely fast, and he takes an absolute load of punishment. Surprisingly, despite the MASSIVE difficulty and complexity spike compared to previous bosses in the game, he gets the same boss theme as everyone else. And remember: he's got no storyline significance. Death Faleon is just a midboss.
Almost every boss may have shades of this trope due to being harder than what's around it. The one that really sticks out is Ligaty: Firstly, there are three of them; one has a weakness to physical attacks, one to Wind magic, and the other to Fire magic, and they each use their respective weakness against you (strangely). The troubles start when you realise your choices are to either attack the physical one, who has a habit of breaking out of hitstun and attacking anyway, or your combo could send you right into an attack from one of the others. Going for the wind one, in which case wind magic limits your movement a few seconds and removes Mercy Invincibility, potentially allowing you to take multiple hits in a row. Finally you can go after the fire one, who you can at least use ranged attacks on, but the aiming can be tricky and while you're focusing on that it's very easy to walk into an attack. Add all that together and it verges on a Sadistic Choice. To make matters worse the less there are the tougher they get, so the final one is nastier than all three combined. The only choice is to exploit one attack they use when all three are alive that makes them stay in place a while defenseless, then continue until you've weakened all of them enough that you can quickly destroy all three before the stragglers get going.
There's also Zirduros. The only weakpoint is its back, it's quite agile while constantly peppering you with projectiles AND the weakpoint is capable of launching mines (which hurt you if you're attacking it in melee). After losing some of its health it can launch a laser that covers a large area in front of it and only gives you a split second to evade. And any of this onslaught is capable of killing you in around 10-12 hits unless you're really over leveled. While not the most damaging method, the only safe way to harm it is to to charge up Earth attacks and exploit the invincibility frames it has. Even better, if you do the dungeon in a certain order this can be the next boss you face after Death Faleon...
In the original Ys 3, the crystal boss in the Cursed Mine was the hardest, if you don't do some serious Level Grinding beforehand. And the Time Ring is required here.
The red ape demon in the Famicom port of the original Ys. Jumps around the room firing highly-damaging nearly-undodgeable omnidirectional projectiles. It's nearly impossible unless you break sequence and go further up the tower for the Infinity Plus One equipment
Gundam Battle Universe doesn't have annoying bosses but some of the Extra missions will make you cringe. The two most famous ones being having to face 3 Psycho Gundams who surround you and will kill you instantly if not dodged and the other is to carry 5 boxes of goods amongst respawning weak mooks as well as the Lanfressia who will ignore flinching damage and always activates its SP attack. If you want the S rank and operator limit unlocked, you have do this.
Eternal Darkness has the essence guardian. Immune to gunfire, too far away to stab, and shoots various projectiles at you. You have to dig in and shoot magickal attacks at him, in a certain timed inteval. At three points he creates and shrinks a barrier till you're within stomping distance, and stomping is an insta kill.
Others Part 2
Peg Leg Pete in Mickey Mousecapade. He throws a constant stream of daggers that randomly change direction and are nearly impossible to dodge, and the only consistent way to defeat him is to resort to cheap tricks like inching up the ladder and shooting, or putting the invincible Minnie up there if she has her stars. He reappears as a Degraded Boss in the Castle, but is even worse there, as there is no where to hide from his daggers. The only way to get past him without losing a ton of health (afterwards, you have to face the Walrus, a Boss in Mook Clothing, followed by Maleficent, the Big Bad herself) is to hope that you find an invincibility fairy behind one of the windows. Oh, and god help you if you left the key to the Boss Room behind, as he will respawn and One-Hit Kill you if you backtrack.
In Aquaria, Octomun definitely qualifies. The only way to defeat him is to get in close and fire at his weak point, a pearl that appears in his mouth, which brings you in range to be hit by a devastating tentacle attack. To cap that, he spawns enemies that can blind you, can darken the playfield by emitting ink, and fires a near-constant barrage of homing shots. There aren't any tricks or shortcuts, either. Ouch.
King Jelly is a horrible mook spawning monstrosity complete with nigh unavoidable lasers and is completely invulnerable except for a very hard to hit rotating Weak Spot. The only upside is that defeating it gets you the undeniably best armor in the game.
Biomeka from Wonder Boy In Monster World, plays this to a T. 2 Forms with a Yellow Green Bar (Highest HP in game), uses Laser cannons which have a full Blue Bar (Highest HP for regular monsters) and those cannons can respawn, and on the second form, has a conveyor belt with a Buzzsaw on it in addition to the laser cannons. You have better have got enough Power or Thunder magic, because you will need it.
Bunji Kugashira from Gungrave can go straight to Hell. The fight starts with him sliding at you; if he hits, he launches an attack that takes out your shield and a quarter of your health. If you dodge, he can turn mid-slide to catch you. If you get too close, he has a melee attack that blows your shield. What truly makes him a bastard, however, is that he can heal if he gets behind cover. The level has two pillars which he gleefully hops around, healing himself every single time you're out of range. The only, only way to win is to throw yourself on him and fire until he's dead, channeling Demolition Shots into healing and never letting him get out of the center of the arena (if he gets to a pillar, the fight will stalemate thanks to his regeneration). Topping it all off is that he has his own "Graveyard Special" (the boss fatality shot that Grave's been using up to this point, which Bunji can use at any time) , as mentioned before. He'll punt poor Grave, sending him flying and come crashing down, causing massive trauma.
And then He comes back in Overdose and does all that...and send weird ghost wolves at you.
Overdose gives us a Sequential Boss, a series of Robot Tanks. At first you're only fighting one, but it is impossible to hit with your melee weapon (which is REALLY bad if you are playing Juji Kabane's campaign, because Juji is the Speedy Melee Character of the three protagonists) as you are immediately knocked back and causes moderate damage. It's also fast and will constantly spam a barrage of missiles or machine gun fire, and can climb on the walls and slide around, pelting you at all sides. And just when you think it's over, when the first tank is destroyed, two more tanks show up...
The Millenion Leaders Hybrid boss in the laboratory stage. You fight it in a circular arena, but every time you empty its life bar, it just regenerates. It also has a painful sword swipe and explosive projectile attacks that can destroy your shield and cause high damage on higher difficulties, on lower difficulties they won't usually break your shield but still often leaves you with a sliver of shield left, and there's no safe cover in which to regenerate, as you'll want to save your precious Demolition Shots for the generators. You're supposed to wail on the boss until your Mission Control tells you to target the generators and destroy them to stop the boss' regeneration. And all the while you're trying to attack the generators, the boss is throwing said explosive projectiles and sword slashes at you. And when you manage to defeat it, when you're riding the lift to escape, the boss comes back and can now body slam your character, which usually breaks your shield. And you have 150 seconds of game time to kill it, otherwise your character won't escape the Collapsing Lair in time.
Ballabird Lee in the original game can be highly irritating, bouncing around the fight area in unpredictable patterns, chipping away at Grave's shield with his machine gun hand and a "grab/throw" move that's hard to see coming because of a slightly screwy camera. Lee's normal sword attack also tends to hit like a Mack truck, often breaking a full shield on Hard or Kick-ass.
Sherry MacDowell Walken in Overdose. She's extremely nimble and fast (even faster than Kabane). Being so fast, it's nigh-impossible to pull off a successful Charged Attack against her. You also fight her in a highly confined area and there is nothing to hide behind to regenerate your shield. One of her major attacks, for lack of a better description, closely resembles a Dynamic Entry. She will use it, and use it often, and has the possibility of knocking off almost 2/3 of your shield power. And it knocks you down, and eight times out of ten by the time your character gets out of their recovery animation, Sherry will KICK YOU AGAIN.
Fangoram in Overdose is also insane. Not only does his gun do insane damage but he'll randomly fire it in every direction and then smash the ground, causing metal support beams to explode out of the ground and fill the level...which makes everything REALLY slow and then you can't see him until his gun shots go through the beams and hit you.
Modarchive Story is a shining example of Nintendo Hard in general, but Doragon is utterly ridiculous. When and where it will spit fire is RANDOM, and you die in one hit. And you have to hit him lots of times. Oddly enough, it's the boss of one of the easier stages, and the Scrappy Level (Zepsi Industries) has perhaps the easiest boss fight in the game.
The robot guard Biscarsh in Klonoa 2 is a nightmare. The first form is pretty easy, providing you know what you're doing. And then it Turns Red. First of all, it tries to turn Klonoa into a Dream Traveller pancake requiring you to grab an enemy, run into the middle and jump over his head in order to hit his weakness. Then he has the nerve to send homing missles after you whilst floating in the air!
The Force Unleashed: Kazdan. Effing. Paratus. The little bastard skitters around the stage way faster than you can, and often slips out of your lock-on. Force Push and Grip are next to useless, as he blocks them nearly every time. He, on the other hand, can break your block with every attack. The only way to really damage him is Lightning...which you only receive at the beginning of the level, and thus do not have time to power up. Damage him enough, and he leaves the stage, hurling detritus at you. If you don't dodge, you take damage from the hit and the fall. Damage him some more and he summons Junk Titans (essentially giant, tough minibosses) to fight you...twice. The highest difficulty is... difficult.
Comparable is Shaak Ti, who, unlike other Jedi bosses, cannot be Aerial Ambushed, a peculiarity she shares with Kazdan Paratus, which is normally your choice to hit a boss For Massive Damage. Then there are her deadly saber combos, her charge attacks, which leave her invulnerable while charging, the fact that she constantly summons Felucians to annoy you, and the exploding slime... thingies on the sides of the arena, which explode if you get too close, which can lead to annoying situations where you're juggled between said exploding slimes after getting knocked into them by Shaak Ti. Luckily, you can do the same to her. And in the second half, she may occasionally go offscreen to have the Sarlacc's tentacles wail on you, which is especially annoying if you have to keep Felucians off your back at the same time. On SithMaster, this battle is... hard. This is, however, somewhat alleviated by the awesome music and the fight itself being a Crowning Moment of Awesome.
In the Wii version, Chop'aa while riding his basilisk. The bloody thing is too large for Pushing or Gripping to work, it's bloody fast, it has extreme amounts of health, and stopping to unleash some Force Lightning all but guarantees getting your head swatted by a giant claw, even if you try to jump away. At least Chop'aa himself is a cakewalk.
Also from the Wii version, Kento Marek, specifically during the rematch in the Jedi Temple. It's as if the man somehow perceives reality at a faster rate than you can; he blocks or counters most frontal assaults or Force attacks, seems to run and jump faster, and will catch you if you're not constantly moving.
In the 360/PS3 version, aside from the poorly-implemented boss fight against the Star Destroyer, there's also the final boss of either path. The Emperor, on the Light Side, can hit you anywhere, anytime, with his Force Lightning, and has a bad habit of flipping on an invincible shield before he chucks four very-damaging, very-difficult-to-avoid projectiles at you. Darth Vader, on the Dark Side, is egregious simply because you've already beaten the crap out of him and blown off half his armor, so why is this decrepit half-machine half-man putting up such a fight?!
The sequel has the Gorog, whose fight never seems to end, and the final boss is Darth Vader, who is turned into a Perfect-Play A.I.. He will block any Force attacks you try, even lightning, meaning you must rely on your lightsaber. Also, in the first half of the fight, he keeps retreating and sending clones at you.
Valis: The Phantasm Soldier (the first game of the series) has two of these. The first one is the twin-headed skeleton dragon (whose most damaging attack - the lightning spell - CAN be blocked with a well-timed spell casting). The second one, which is INFINITELY MORE difficult, is Reiko, who has the Final Flash spell that deals just under 50% damage every time it hits you, and cannot be blocked or countered. Oh, and guess how strong it is in your hands?
Jet Force Gemini features the Eshcebone Mantises. Yes, there's two of them. Giant cyborg mantises with a ridiculously wide variety of attacks, fairly small weak points for most of the fight, a dark battlefield, AND THERE ARE TWO OF THEM OH FSM WHYYYYYYYYYYYY
Mizar, even by final boss standards, is infamously difficult. He has many nasty attacks, including a swarm of meteors, shockwaves, ice blasts, and worst of all, a ball of electricity that follows Juno around the small platform he's on, and takes off a whole bar of health if it connects for one second. But what makes him truly difficult is that unlike all other bosses, Mizar has no pattern to his AI. He launches all of his attacks at random.
The Ecco The Dolphin games are just plain hard in general, but the final boss of the first game stands out less because of her own difficulty and more because if you lose, you have to repeat the five minute long scrolling level with no checkpoints where a wrong turn means instant death. And, as if to further taunt you, the game gives the password to her chamber after the credits roll.
This was fixed in the PC port, where losing against her just starts the fight again. Also, IIRC, the scrolling level was given checkpoints.
Asterite, anyone? You have to precisely hit 4 targets out of 32 that constantly move around, if you hit anything else you have to start the sequence over. All the while it shoots lightning bolts at you and you are running out of air. It also takes at least a minute to get to it from the start of the level and there is no checkpoint when you do, so if you die you have to start over from the top of the level.
In Defender of the Future, the generator in "Sleeping Forces of Doom" is not actually that hard, but best of luck figuring out how you're supposed to destroy it in a timely manner, without frantically using moves at random hoping something happens or grovelling over to GameFAQs for help. Sonar the generator's arms when they're picking up rocks fed to them from the chutes until they blow up. When the arms are gone, use the Sonar Grab to pick up the rocks and fling them into shield around the generator.
Defender's final battle is a Womb Level with very little room to manuever, a slightly less-than-intuitive way you're supposed to go about destroying the Foe Queen's heart, and not one but twotime limits counting down to your inevitable doom: Ecco's air meter (which is nigh impossible to replenish in this level), and the steadily rising pool of toxic blood from below that will eventually flood the chamber and kill you.
Reika Kuze, a.k.a. the Tattooed Priestess from Fatal Frame 3. She absolutely LOVES this move where she turns the screen black and white, makes it so dark that you can only see yourself, you run like you're moving through jelly, and she chases you. If she touches you, it's a one-shot kill. It's hard to even SEE her, let alone avoid her because you move so slowly.
As difficult as that boss can be, the Kusabi in chapter 8 was harder. He's a challenging enemy in his own right, and you have to fight him with Kei, by far the weakest character. If we're talking the Fatal Frame series, the Family Master from the original game is That One Boss.
All the bosses from Fatal Frame 1 qualify. Considering the game mechanics made it possible for the ghosts to move faster than Miku, it was very difficult to get a lock on the ghosts that liked to either strafe or teleport. The Family Master was tough, but Ryozo Munakata was just as bad since he mainly moved by teleporting around the area. Then, if you're playing on Nightmare Mode, he has this nifty attack where he mesmerizes Miku into coming towards him so that he could grab her. Then there's the end boss Kirie whose ONLY attack is the insta-kill one and who could only be hurt by a fully charged shot. Oh and she regenerates health over time.
The Monk from Fatal Frame 1 is another spirit who was a pain to fight. He not only likes to teleport, but he also tends to bumrush you so that he can deliver a nasty kick to the head. He usually has a fairly large amount of XP and getting a charged shot is annoying.
Weldar from Banjo Tooie. At the start he shoots energy balls (simple to dodge), but then he tries to suck you into his giant mouth. You shoot a grenade in him (which requires you to stand still and crouch), then he shoots some baddies at you. Beat them and then he chases you around. After that he puts an electric grid on the floor, which you must hop around on in tandem with the same moves. To add insult to injury, his Boss Room is very out of the way, and you don't (directly) get a Jiggy for defeating him.
Lord Woo Fak Fak in Banjo-Tooie. He moves so quick, and unlike Mr. Patch he moves into you — not hurting you but screwing up your aim. Hitting him becomes a matter of luck. Even worse, you fight him underwater, in a ridiculously confined boss room, making it even more impossible to put enough distance between you and him to manuever effectively. And in Replay Mode, you don't get the luxury of cheats or the infinite-ammo and easier-to-control Submarine.
Mr Patch, in all of his incarnations. In Banjo-Tooie, his battle requires you to be flying in the air, picking off his very specific weak spots with slow moving projectiles in a first-person aiming mode. His erratic movement and Kazooie's wonky flying made wasting Grenade Eggs almost inevitable, and the slow flying made dodging the exploding beachballs a nightmare. Oh, and he gets smaller every time you hit him. Nuts and Bolts had you face him two times - in Nutty Acres, his patches are less obvious and your plane (if you have one) won't be advanced enough to turn quickly, meaning you either have to wrestle yourself into position or slam into him too many times, and in Banjoland, dragging him into the cactus is difficult because he breaks away every time he gets a puncture and the helicopter controls (assumng you used a helicopter) are wonky-tastic.
Chili Billi or Chilly Willy, depending on whom you fight first. The first dragon is easy, but the second one is much more difficult. He will lead his shots, slide his giant tongue across the stage very fast, and the cannons you use to damage him disappear after a few uses. Plus, he has much more health than the other dragon.
The Hag 1, the final boss, is ridiculously difficult, even for a final boss. It has an absolutely enormous variety of attacks, including spinning lasers, mortars with shrapnel bursts, chasing you with a giant drill, chasing you with a giant drill while spinning lasers, spawning minions, shooting off magic blasts that use a quiz question to determine their speed, toxic gas that will kill you after your oxygen meter runs out, and a very fast rapid-fire spell. Now, you do get life upgrades and cheats (like HONEYBACK which regenerates health)...except on Replay Mode, where you have just five honeycombs and no cheats. Good luck.
Any battle against Axel Gear involving two Mechas in the Rocket Knight Adventures series. On Normal, they're bearable. On Hard, you better hope you have full health walking into it. And, what's worse, the SNES Sparkster game has a special surprise for those that defeat the Final Boss on Hard which makes the Axel Gear fight look easy.
The God of War series has a handful of these, but the final fight in the original game against the eponymous God of War is a nightmare on any difficulty other than medium, plus it's a two-parter with an extremely difficult War of the Clones wedged in between. Pure evil.
The War of the Clones part deserves elaboration. You're fighting a Battle in the Center of the Mind against Kratos doppelgangers who are trying to kill your wife and daughter. You can restore their health by hugging them to transfer your health to them, but that leaves you vulnerable to attacks which will also damage your family. At any given time, there are seven clones on-screen, and they respawn a LOT. If you get grappled or knocked down even once, it wastes precious seconds, during which the clones quickly slaughter your family.
God of War II. First Titan-mode rock minotaur? Not much of a problem. Number 2? A resilient boss with few openings AND infinite respawning harpies that can 3 shot KO you on titan. There's a reason most guides for this fight use the phrase, "metric assload of luck" liberally.
Theseus on Titan, who serves as a huge difficulty spike, even compared to the Nintendo Hard opening act. He can combo Kratos to Hades and back in his first form, proving to be more of an unpredictable opponent than the Mooks you've been facing so far. And then comes his second form, where he starts spamming projectiles at you from safety, starts summoning two Minotaurs at once to fight you at the same time, and causing large crystal spikes to pop up from the floor which, on Titan, one-shot you. Add all of this on top of the fact that the only way to hurt him in his second form is to shoot him with your incredibly weak bow. And your magic is limited, so the only way to restock it is to run around dodging attacks and killing the Minotaur for blue magic orbs. And it'll take several cycles of this before you even get the chance to finish him off. If you die, you go back to the first form. He also gets a cheap shot that wipes half your health if you're not blocking when you choose Restart. Have fun.
The Cerberus Breeder in God Of War 3. He spits out kamikaze dogs at you that explode. Sure you can kick them back at him but they don't do a lot of damage. What makes it worse is the Satyr Generals that come to back it up after each time you take off one of its heads. On harder difficulties, you need to turn dodging and blocking into an art form to survive.
Descent: Many of the bosses, due to being armed with the most powerful weapons in the game on top of being accompanied by a small army of Mooks, and some of whom are Mook Makers to boot. However, the Ice Boss from Descent II takes the cake for pure frustration. He fires homing Flash missles (which blind you) and an Omega Cannon (the strongest primary weapon in the game) which has been haxxored so that it also blinds you. Meaning that unless you stay up in the passageway leading into the Boss Room (which protects you from most of his attacks), you'll likely be flying completely blind for the battle. And he's immune to energy weapons, meaning that the only two primary weapons that even affect him are the Vulcan and Gauss cannons, for which ammo is rather limited.
The Fire Boss may be even more frustrating. Instant-kill homing Mega Missiles + super Phoenix Cannon + random teleporting + lack of cover = pain. If you wasted the cloaking device, you're fucked.
Luigi's Mansion has Boolossus, a horrendously hard boss battle that involves freezing a bunch of tiny boos in order to defeat it. Unfortunately, as the number of boos get smaller, they become harder to hit, until it's almost nigh impossible to hit the very last boo with your freeze weapon. And they know when you are using the ice, because they run away when you do. Its almost impossible to get them unless you shoot while they dive bomb you, and when that happens its like impossible to aim before shooting.
Technically a mini-boss, but Sir Weston is easily the most difficult portrait ghost for the perfect run. His room is covered in ice, so it's very difficult to suck up him up in one go.
The final boss in True Crime: Streets of LA. Not only does it not make any sense, but this is where the difficulty spikes horrendously. Specifically, every single boss in the game up til the end could easily be beaten with simple Button Mashing, whereas the final boss had to be beaten with an actual strategy (blocking then counter-attacking), which most players would never have guessed since the game never hints at this and Button Mashing got them all the way to the end just fine.
Onslaught (2009 FPS) has the Mission 8 boss which has turned into That One Boss for many players. It might be because the boss has a tendency to correct its aim while using its extremely damaging beam attack that you're supposed to sidestep. Also the small arena and spawning smaller enemies make it very easy to sidestep into an obstacle, making even the usually easily dodged jump attack a threat.
Shadow of the Colossus is a very enjoyable, artistic action-adventure game. The 9th colossus is a complete ass. Essentially, he's a giant turtle. The only way to successfully climb onto him (the point of the game) is to lure him onto stepping on some geysers. He frequently steps over them or walks just a few feet near him, making that an exercise in frustration. If you get him to step on a geyser, you have a small window of time to shoot the underside of his feet so he flips over. Then, you have to run around and climb on his belly. When you're about to finish climbing, he stands up. If you aren't positioned right, you fall off. If you manage to stay on killing him is easy. The boss isn't incredibly lethal and doesn't sound hard to beat in text, but all the components make him incredibly aggravating and unfun to fight him in the game.
With the 9th, at least you have a reasonable chance once you get on, it just takes time and luck. The 16th and final colossus, however, is (metaphorically) a tremendous cock. All the wonderful landscapes in the game are NOT present, and the whole fight is in shades of black and very dark grey. Just in case you have the superhuman vision to dicern color in this mess, the camera abrubtly turns into a big pile of ass, too. Oh, and if you fail any part of the second half, you fall off and have to do it all over again.
The eleventh Colossus? A comparatively tiny (only the size of a VW bus or so) colossus, something like a cross between a pit bull and an actual bull. If you happen to fall into its pit and fail at dodging its attack even once, it'll knock you around with abandon, stunning you completely with each blow and attacking again just as you begin to wake up.
The 4th Colossus can eat a bag of ass. For those who don't know, it's a giant horse. The area around you if completely surrounded by...tombs probably. This thing's only climbable area is on its tail, which is too high for you to reach. So you get it's attention near one of the tombs until it starts attacking the tomb like an ass. You need to run to the other side, since all the tombs ar connected under ground. The issue? 1. You need to be within striking distance for him to even GIVE a crap you're there. 2. You need to be FAST, and since a gentle nudge will send Wander head over ass, that's difficult. 3. The Colossus has ADD, and making him stay near the tomb in time to run over to the other side, let alone to the colossus is pretty difficult.
The 15th colossus, Argus, requires the player to complete a very convoluted set of maneuvers in order to even have a chance at reaching his weak spots. Dormin's hints are cryptic as usual, and it can often take players a long time to figure out the correct solution to the puzzle. This is not aided by the fact that Argus walks faster than Wander can run and is constantly trying to smash him to bits while the player attempts to think.
The third Colossus, on normal mode, is a surprising jump in difficulty from the first two, with the added inconvenience of there being a long drop below the arena, necessitating a long climb (and possibly a lengthy swim) to get back to the boss if you fall off. On hard mode, the thing's capable of killing you in a single hit from the attack you have to get it to use before you can climb onto it (at least twice if you're using the normal strategy, one of which must land on a specific position), and it has an additional, necessary weak point located inconveniently out of the way of any ledges.
Speaking of Difficulty Spike, Ico seemed to have this with the game's final and only boss. In all the other fights you've been in protecting Yorda from Shadows, they could not kill you. Insted you fight the flippin' Queen who can insta-kill you, and you can only hit her once for every opening she presents. Did we mention that your only cover from her attacks disappear after a certain amount of hits? Good luck in getting those hits in.
There's also the giant babies. They are ludicrously fast, frequently speeding into your view, stunning you with collision damage, then speeding back out. Good luck even hitting them. What's more, they transform into a normal, rescuable baby when they are defeated, meaning they must be beaten to finish the level.
The second form of Sir Sweet in Prinny: Can I Really be the Hero is one of the few bosses with a reputation for literately inflicting physical pain on the player themselves. Does not play by the rules of boss fights meaning that you have to fight a Nintendo Hard boss without being able to stun him by wailing on the attack button for two and a half minutes per life, and you will lose a bunch. About as painful as the micro wave chamber.
Chose the Magma Hideout as your 6th stage? You end up battling Tsukikage, Hoshikage's superpowered eviler side. She uses all the same attacks, but at triple the speed.
The sequel, Dawn of Operation Panties, Dood!, introduced a new handful of overpowered bosses, including:
Chili, Pow and Der on the Stage 5 version of Unlucky Swamp. Besides having to battle three bosses simultaneously, you start this version of the fight SURROUNDED. The sisters bounce back and forth erratically, causing you to miss your hip pounds, and stunning one will only give the others time to gang up on you. Chili has to be taken out first, as she can summon lightning bolts and, given enough time, heal the damage dealt to her and her sisters. And the other two sisters summon homing skull mooks the whole time. The Deity that they summon in the Stage 6 version is a cinch by comparison.
Mustard in Sakura Palace 3+4 may be a bubble headed cheer girl who doesn't fight directly, but the monsters that she summons always manage to be in just the right spots to hit you out of your combos, allowing her to teleport to another part of the arena with an ever-increasing pep squad that only manages to get in your way.
Lee Jiang Long in Undersea Volcano 6, despite being a gigantic dragon, has a ridiculously small weak point that's constantly moving; this means that your hip pound will most likely have no effect at best, and possibly send you screaming into the abyss. Its attacks cover a large portion of the tiny area that you have to maneuver in, and an endless amount of homing skulls rise from the pit for good measure.
Direct from Ren and Stimpy: Veediots is the "battle" against Ren at the end of the Stimpy's Invention level. You have to simply toss the Happy Helmet onto Ren's head to finish the level, but you are given no indication on what to do, and trying to throw the helmet at Ren is a challenge in itself. The helmet can barely reach the platform Ren is on, and if it goes on the platform but you miss him, it will get sucked into a tube and brought back down to your level, allowing you to try again. There's also two floating platforms, but you can't reach them, and they're no help at all, since the helmet slides off them almost instantly. To add insulf to injury, all Ren does is pace back and forth randomly at the top of the screen, saying "You eediot!" over and over again.
People who have played Toy Story will often comment on their nightmarish encounter with The Claw. This is officially when the game gets hard for some. You have to use Woody's pull-string to throw squeaking alien toys at the Claw before it carries Buzz off. It's harder than it sounds, particularly on the SNES, where the hit-detection on the aliens is weird. Also, you have to survive about five or six of Sid's coins before he "runs out," and Buzz gets closer to the edge each time. (Mysteriously, the storyline tells us that he has managed to capture Buzz and Woody between levels).
On the Sega Genesis version, the aliens are easier to hit — but there's this random swinging cable that you have to keep avoiding.
Carabs, the Stage Four boss of Astro Boy: Omega Factor. The SHMUP sections of this game are similar in ways to a Bullet Hell, except that Astro Boy's hit box is twice the size of a standard SHMUP vehicle. Carabs will take off half your life if you touch him, and he takes up two-thirds of the screen. Trying to dodge through him is an exercise in futility, thanks to how dodging jams up in these sections. Oh, and if you try to fly under or over him, he'll change direction to slam into you. For extra fun, do this in the all-damage-doubled Rebirth mode!
For first-time players, North can be a giant brick wall, as he seems to guard any attack, and instantly retaliates with a nasty counterattack. Even when the player figures out what to do, he's still tricky.
Graffiti Kingdom: Most of the bosses are pushovers, but then you run into Telepin. He floats, dodging a lot of the faster physical attacks, spins around the arena making the Most Annoying Sound, can block, possesses six weapons that can combo about half your health bar off, and fights you in an arena that creates large explosions in short intervals. He's not even a Wake Up Boss; The boss after him is much easier.
Gigan from Godzilla Monster Of Monsters. His attacks are to spam you with laser blasts that can't be dodged and to trap you in the corner with the buzz saw on his chest and just steadily drain your health. The strategy to beat him consists of hoping he dies before you, and praying he decides to let you out of the corner (Very often he doesn't).
The Wii One Piece games have the battle with Gecko Moria in Unlimited Cruise Episode 1. He spends the majority of the battle running away from you, which makes dealing damage very difficult. As he flees, he consistently launches annoying shadowy projectiles. It gets worse after you manage to bring him down to half health. He begins frequently abusing his super, Shadows Asgard, an annoying, almost impossible to avoid attack that given your levels is an instant kill for whoever it hits. Luckily you have nine characters to use, but the fight becomes a race to catch up to and deal damage to the boss before he murders everyone with Shadows Asgard.
The Legendary Starfy: The final stage of the final boss, which is literal button-mashing so fast the only way I've heard of that could CONCEIVABLY work is to pause the game and put it down when you get tired. Oh, and you do this TWICE. Smouldering hate.
The Captain from Henry Hatsworth In The Puzzling Adventure is widely considered the hardest boss in the game. The sea dog himself isn't really a treat as he's a senile, decrepit old geezer in a wheelchair, the real menace is his hulking monster of a nurse who uses him as a bludgeoning tool. Not only the nurse's attacks cause a lot of damage and are tricky to dodge but she can also pitch capsules that will hatch into monsters. It becomes even worse in the last phase that takes underwater, where both the captain and his nurse become temporally invulnerable and you have to dodge them while taking care of their minions until you building up your Super Meter and unleash Tea Time to finish the crazy old man. The icicles that tend to rain down right before that phase and temporarily make columns unusable should you let them reach the bottom screen certainly didn't help.
The Machine is infinitely more frustrating. The Captain doesn't have a One-Hit KO that he busts out extremely early in the fight, for one, and another that he spams later on. The Baitand Switch Boss beforehand didn't make things any easier, either.
In the higher difficulties of Iji, especially Ultimortal, the second Asha fight, in Sector X, is generally considered the single hardest boss of the game, and being the main obstacle that stands between people and Turbo Mode/Null Driver/Sector Y. Few people are capable of beating the second Asha fight in Ultimortal difficulty without the use of the Checkpoint.
The reason it's hard is reaction time. He has about 10 different attacks, and each has one or two ways to avoid it, but will always hit you if you're still. The problem is that you've got a window of generally about 0.2 seconds to see him appear, notice what position he's in and hence what attack he's going to perform, and start your dodge before it's too late. And he teleports around like crazy between attacks to confuse you, and fake images of him start appearing halfway through the fight. From 7:43 onward this video shows the problem very well.
Also from Iji, Proxima on the higher difficulties. This robotic boss can unleash a ton of attacks at once, many of which are very difficult to dodge (or else dodging one will get you hit by another), and unless you have very good weapon stats (which are not available on Ultimortal anyway) the only way to beat it is to hit it repeatedly into an electropod. The catch is that you have to wait for it to recharge, an increasingly long time with each difficulty, and during that time there's nothing you can do but try desperately to survive.
Any boss after Round 2 in Bonk's Adventure, they're such cheap bastards you're almost guaranteed to lose a couple lives. And worse, you have to fight a Boss Rush of the first four bosses in Round 5.
They're all pushovers... except for that fnarking Ballerina... THAT FNARKING BALLERINA!
Captain Cook in Bonk's Revenge. The Climax Boss of the game, he is a large leap in difficulty from first three bosses. This is the first boss to have two forms, and his second form is a big pain in the neck; you have to wait until he moves to his lower position(and shoots a deadly fireball) to jump onto and hit him, which is easier said than done without taking damage, and his attacks take off a at least a full heart with each hit.
Reapermon in Digimon Rumble Arena. The final boss of the game, and clearly designed to be the cheapest bastard on the face of the planet. His triangle attack results in two hits that cause your character to flinch, making you completely unable to avoid the ten-hit rush that immediately follows. Just to top it all off, he can (and will) follow it up with his flame attack, in which he causes a gout of flame to rise up from the ground and hit you another eight or so times. The worst part, however, is that this sequence of eighteen to twenty hits in three seconds will daze your character—leaving you stunned and completely defenseless against the same combo. Which inevitably leaves you dazed once more, allowing for a permanent stunlock until dead. Projectile spam is one's best bet—so help you God if you're playing a short-range character like Wormon for the sake of unlockable characters.
Ninja Gaiden: In the Xbox games, every boss is That One Boss for somebody. Special mention to Murai in the first game. He's the first boss in the game and a good number of people need help fighting him. He can block your attacks, dodge your magic, dash attack like you can, combo you for massive damage, and grab you (which is unblockable).
Alma from Ninja Gaiden Black. Alma is the queen of That One Bosses, the That One Boss from which all lesser That One Boss sprang.
All of the bosses that force you to use the bow also qualify, if only because it's quite the change from being able to use Ryu's melee Hyperspace Arsenal.
Ghost Doku's backup on Hard Mode (where every boss is accompanied by some Mooks that get reinforcements every time you damage the boss) is especially annoying, as the Nunchuks are ill-suited to fighting him, but the only thing that can effectively kill the ghost fish. Waiting him out and hoping to outlast him by burning through your Elixirs of Spiritual Life is also not an option, as he can drain your health.
And the level before him qualifies as That One Level, too, which makes the boss fight infinitely more infuriating. There's one save point quite a fair distance from the fight (first you need to find some keys to open the way to him), and the entire time you're in a labyrinth filled with ghost piranhas. You fight dozens of them at any given time and if even one hits you, it starts gnawing away at your, stunlocking you, and opening the door for every single other one to hit you. That's not even the best part: the amount of time you spend stunlocked isn't set. Each of the piranahas attacks for a set period of time, and that means depending on how quickly they hit you, by the time the first wave has left and the second wave is almost done, the first wave comes back and continues the stunlock. The only way to stand even a ghost of a chance is to use the Vigoorian flails or lightning ninpo, but the former still leaves the chance you'll get devoured as detailed previously, and the latter burns up ninpo and elixers that would otherwise make the fight with Ghost Doku less difficult.
The three NES Ninja Gaiden games had many tough bosses, but the worst was probably the final boss Jacquio in the first game, because his fireballs were almost impossible to dodge, and losing against him sent you back three levels. Getting to him with an Air Slash was the only way most people beat him.
While there is a some strategy in dodging his fireballs, what's worse is his hitboxnote They work like the eagles only at full speed - if you're sufficiently far away, just keep moving and they'll fly right off the screen. Being triangular in shape in a day where squares were the norm, his hitbox (which includes contact damage) is a bit bigger than what you think. And he takes off 3 HP per contact, versus 1HP per fireball.
Perhaps made worse by the second game's triple boss rush. Not only did it send you back to 6-1, but you had to do it without health refills.
If you're playing single player on Professional difficulty in Resident Evil 5, be prepared to face hell against Wesker and Jill. This is mostly because Sheva LOVES running off to get killed, on a difficulty in which 1 hit sends you into Dying status. The only way to beat Wesker on your own here is to bring a rocket launcher and pray you can hit him with it, which tends to be ridiculously hard to do.
Ndesu, aka The El Gigante of Africa. You are caught in a truck that you cannot move, and the only way to not be hit is to A. shoot him enough so that the attack is disabled (ala House Of The Dead, but without the helpful meter), or B. hit the action commands that come up for a half-second. Chances are, you're gonna get the A. part in spades, until he pulls a giant boulder out of the ground, which you need to shoot before it hits you, otherwise that's a massive chunk of your health. For the B. part, chances are, cause the weapons you get are a RPK) and a minigun, you're gonna be busy firing, and if you hold over, and THEN try to hit the action commands, you fail it. Also, random enemies like to come in at about the halfway point, and shoot you with the flaming arrows, and did we mention that you can't heal yourself if your health is too low, because you're in a truck. No matter how bad that boss is on the console version, the PC version is much, much worse. The keyboard action commands are very poorly located, and a lot of keyboards won't detect the buttons properly anyway.
The fights with Nigel Bloch in Agent Under Fire qualify. In the first one, you're on a tram rail with no cover. There's a wave of guards then Bloch comes out on the platform of the central control tower. He has perfect accuracy with his weapon, even while recoiling from being shot. Then he opens up the doors below to reveal lava that slowly damages you in a subversion of Convection Schmonvection. You have to take out another wave of Mooks, then use a video guided rocket launcher to take out three lights above. Go too slow, miss, or take too much damage in the fight and you gotta start all over from the beginning.
Ace Combat Zero: The Belkan War has Alberto "Espada One" Lopez. Don't laugh at the fact that he's "only" piloting a starting plane, for he can be very hard to hit and can outmaneuver Bigger Sticks quite easily. Real horrorshow, that one.
Ace Combat X: Skies of Deception gives us Alect Squadron in Fenrirs. Think Alect Squadron in "only" S-32s was tough? Think Fenrirs with relatively nooby pilots were challenging? Try them together. In addition to being fiendishly agile, their Invisibility Cloak meant that you could be fired on from seemingly nowhere, making dodging difficult, and you couldn't get a stable lock-on since the lock would break every now and then, so even QAAMs had rather reduced performance. You did have the option to destroy the generator powering their invis, but that did not affect their lethality. Fortunately, once you did defeat them the rest of the mission was, even objectively instead of relatively speaking, easy.
Ace Combat 6: Fires of Liberation graces us with Ilya Pasternak in his missile swarm hurling Nosferatu and a bunch of small drones that are pretty hard to hit. On top of the missile swarm attack, the Nosferatu is also capable of monster acceleration and a dime-sized turn radius which allows him to dodge a missile whenever the fuck he wants. So on higher difficulty levels, the fight consists of Ilya launching the missile swarm, and then hauling ass roadrunner style. Meanwhile, his numerous ridiculously agile drones keep you from achieving a lock quickly and fire their pea shooters at you. By the time you do get a lock, he's already turning for another pass at you.
Queen Bee from E.V.O.: Search for Eden. She's a much nastier version of the King Bee from earlier in the stage, and he was pretty unpleasant.
Birdman King too.
Then there's Cro-Maine, who can hit you off the screen (and the attack HURTS, too)
The Final Boss, Bolbox. He's an eight form Boss Rush that pits you against seven previous creatures, all strengthened to various degrees and most of them can be considered their own boss while Bolbox attacks with his hand. Luckily, there are two parts that can't even harm you and a few of the bosses being extremely easy, but dying once sends you to the map and, thankfully, you don't have to go through The Very Definitely Final Dungeon again. You know that a boss is hard when a trick that fully heals you will still give you trouble if you didn't grind off of the preserved Tyrasaurs.
Nephtis in Zone of the Enders: The Second Runner, first off, none of your weapons damage her, the only way to damage her is to knock Nephtis into the surrounding scenery, this becomes most grating after the train sequence, where you're inside a cylindrical room with multiple levels, and nothing to grab onto to use as a suitable projectile/defence. With fricken Clods all over the place which not only try to grab and hold you in place while Nephtis does its kamizake run, but they confuse your lock-on function, in which adding to Nephtis' unpredictable flight path, makes it impossible to lock onto to that thing until it's too late.
Gets even worse in the fight after that, when the AI from Nephtis infects a friendly robot and you have to beat it without actually damaging it. "Cross swords and grab! Cross swords and grab!" How about...FUCK YOU?
The fused Anubis and Aumaan Anubis in the last level in the 360 version. You only have Zero Shift available, all other weapons had been destroyed in the trip. Including Vector Cannon which could bust through the boss's shields with ease.
Most bosses in Sunset Riders have fairly easy patterns to deal with once you figure them out. Chief Scalpem (renamed Chief Wigwam in the SNES version) is not one of these bosses, as his pattern involves jumping all over the place and throwing knives freakin' everywhere. Next to the final boss, he's the hardest boss in the game, and the final boss is only hard because he takes an ungodly amount of bullets to kill, not because he has difficult attack patterns. As an added "fuck you" by Konami, he's also the one boss that you don't even get the pleasure of finishing off, as his cute little sister runs in and begs you not to kill him.
From the same game, The Smith Brothers. If you don't have your weapon powered up (and you lose your upgrades when you die); you will have a hard time. Their combination of throwing bombs and lanterns at you will cost a lot of lives. Only through a combination of patience, a lot of jumping, flipping, and balancing on the chandelier at the center of the room can you beat them.
Bomberman has it's fair share of incredibly tough boss battles...
The fight against Mantis will first start off in her cave, in which the floor is incredibly slick and difficult to maneuver around. She happily enjoys jabbing you with her enormous mantis-like front legs (and jump up to attack with both), climbing along the walls to spit out baby-spider-like things, and sliding herself into you. However, the battle really goes hay-wire when you've damaged her life meter to halfway, she breaks the floor and drops you down to her web, in which there's a good chance you'll miss it and fall to your doom. Considering she takes up a good portion of the screen, if you don't fall to your doom, you still have the possibility of doing so because you walked off the web, all the while she still tries pick and prod you to death. If you do fall and you haven't collected the 100 gold cards yet, Sirius will come to help you up, but upon collecting all the gold cards, you'll just fall and die.
The fight against the Cerebus is insanely difficult because the fact that all his weapons have an enormously wide and short range, and the room you fight him in is very small and enclosed. His machine gun fire is pretty easy to avoid, but his homing missiles from his two primary canons and his smaller homing missiles from his container "shoulders" (it's a hovering robot) can and will force you into a trap. What's worse, if you haven't destroyed his arm canons and you hang alongside the wall too much during his attacks, he'll do a back-flip loop with enormous laser blades and try pulverize you into the wall with a mighty whack. There's also another attack he uses that creates an odd light glow in the middle of the room that slows you down, but allows him to keep moving at an insanely high speed, and walking into that light will cause you to die by shrinking out of existence (however, you can get a gold card if you kick a bomb into and also disable the beam). Add all of this into the fact that he dodges all bombs kicked at him and that this is only the "normal" level of gameplay (hard is much worse), and you have the ultimate "high-tech harvester" as the name of the battle implies.
Nightmare Creatures has the Sewer Snake as the very first boss. This snake has five heads which shoot out bursts of flame at ridiculous speeds as its first stage attack. This means that your character is going to be spending a LOT of time lying on the ground while engulfed in flames. The second stage (should your character survive the inferno long enough to knock down the five support beams) is spent trying to attack the heads of the snake as it moves around the fighting area. Did we mention that this is the first boss fight?
The giant vampire boss from Horror Island, the third level of Rainbow Islands. It was infamous in its day.
Think the Wii version of A Boy and His Blob looks cute? You'll be changing your tune hardcore after you encounter The Beast at the end of World 2. You have to lure him close to you, create holes in the ground, and let airborne mines drift down to blow up on him. Sounds simple, right? Except that, while the Boy and Blob toddle around at an appropriately little-boy-ish pace, the Beast is lightning fast, vicious, and so friggin' huge that even the highest platform in the arena isn't safe from his horrible back tentacles of oozingDOOM. You have a literal safety bubble, but can't use it and the hole you need to defeat the boss at the same time. Even the developers themselves said he was too hard!
7th Force's boss battle has a whole stage dedicated to it and, by Alien Soldier standards, its 5 forms aren't really that hard. Problem is, there's no way to heal in 3 of those forms AND you are on a tight clock - while Valkyrie and Artemis Force are very easy, Medusa and Silpheed are major time sinks unless you know exactly what you are doing and Sirene is just so very hard, being a fast target with crazy range, a small weak spot and a tricky underwater stage filled with mines that circle around you.
Epsilon-1, the main character's Superpowered Evil Side that somehow manifested into an evilHumongous Mecha eagle bent on destroying humanity. Its weak spot, the head, was blocked by its two damage-absorbing talons, making it hard to squeeze in shots. Secondly, the only weapon effective against it was the Lancer which did huge damage, but each shot cost a TON of ammo. Worse still, you might have probably run out of ammo for it after a Boss Rush consisting of three other bosses, two of which were not exactly easy. Thirdly, EVERY SINGLE ONE of Epsilon-1's attacks did 200 damage to you character (enough to kill you in say, 4 hits). The only saving grace you had against this fiend was that it was one of the few bosses that did not do any Collision Damage to you.
Rimfire from AC: Last Raven. Savvy enough to come immediately after a weaker boss, he's got 2 back mounted-chain guns, and duel wielding 4 barreled machine guns. He'd be a Wake-Up Call Boss if every other boss wasn't nearly as bad.
The Jabberwock from American Mc Gees Alice. Ironically, Alice fights him twice, and while the first time is a Hopeless Boss Fight, it's much easier than the second time, where this Trope is truly the case. The biggest difference from the first and second fights is that he has enough room to truly utilize his ability to fly in the second one, letting him attack from the air, directly above Alice (which is nasty enough in a game like this) and his primary attack sets Alice on fire, causing her to flail and scream. (If there's any consolation, Alice will have added the Jabberwock Eye Staff and Blunderbuss to her arsenal between the two battles, and those are a necessity to winning this one.)
The final boss from Eureka Seven Vol 1: The New Wave is just plain evil in both forms. Your first fight is against him on the ground while you pilot the Nirvash, the absolute worst LFO or KLF for this battle since it has no weapons and he has an 8 pod missile launcher and he hits just as hard as the Nirvash does. Your only defense is your excellent offense and your boomerang which are both pointless against his massive forefront blasts. The second part has you battling him in the air during lift combat which up until this point you had been in only one other one: The training Session for lift combat several chapters back.
Nearly all of the boss fights from the first Rayman are pretty hard, but some of them just take the cake. Perhaps the best examples include Space Mama and Mr. Skops; Space Mama dishes out a merciless assault of fast, hard-to-dodge attacks while Mr. Skops has a homing attack that is nearly impossible to dodge. Also, one part of the SequentialFinal Boss fight is ridiculously hard, especially when compared to the rest of the phases—including the final one.
Rayman Origins has Murray. He's a very large target that takes up half the screen and fills that small space with smaller worm-like creatures. On his final attack, if you don't move out of the way or strike the weak point, it's a One-Hit Kill with a large hitbox; the fact that Murray comes barreling out of the side of the screen with little warning really doesn't help. While the underwater controls are actually good in this game, that's merely a consolation.
Rayman Legends has the Cloud of Darkness, the fifth world's boss. You have to fight it with the fist projectiles, it's very difficult to avoid (but other than Collision Damage, it has no other attacks), and you have to fight it three times. The first, it takes the form of a giant hand, and it chases you around the sloped arena that is tough to navigate in. The second, you have to fight in mid-air, there are two flying entities, and there are also two giant sawblades right in the middle. The final is the worst. It's a giant target that you have to fight on three tiny floating platforms, and it takes memorizing its movements to survive. Also, you have to go through a tricky platforming section between each phase.
The Oni boss from Muramasa The Demon Blade. You need to hide from all of its attacks, otherwise, kiss goodbye to approximately 4,000 health on Muso (Normal). Sure, there are rock piles for you to hide behind. But then there are all the little demons that, while they don't do any damage, cause you to stand up and reveal your hiding place. And the way the controls are set up, attacking makes one travel out from behind. Oh, and the boss can knock over your hiding places. Given that even without grinding you have about 6K health at this point, still...lots of healing to be had. And if you haven't gotten around to buying some of the higher-ranked healing items, this can take a while...and you'll likely get picked up again. Oh, and it has a health upgrade from the previous bosses.
The Dragon boss is big, has more invulnerability frames than you'd think, regularly blackens the screen and turns invulnerable, sprays enough projectiles to turn the game into a bullet-hell shooter, not all of which are deflectable, leading to many broken weapons, and, just to put the cherry on top, has a nasty One-Hit KO that's hard to dodge, fills the screen, and turns him invulnerable while spawning projectiles when it charges up.
The Dual Boss battle with the Torturer and Deviant 1 in Soldier of Fortune II. Deviant 1 attacks with a sniper rifle, while the Torturer is Made of Iron and armed with an instant-death M60 machine gun, and there's almost nowhere to hide.
The Typing of the Dead has the boss of Chapter 3, Tower. For the first phase, you are given a question and 3 answers; answer correctly and you damage it, answer incorrectly or take too long and you take damage. However, some of the questions can be confusing to answer and you don't have a lot of time. Then comes the second form, in which Tower's last head swims or burrows around and you have to type the phrase shown before it bites you. If you're in the pool, you have plenty of time, but if you're in the sand pit it's harder because the phrase doesn't show up until after the head surfaces, which leaves you very little time.
Then comes The Magician in Chapter 5. For the first part, you have to type its phrases quickly and without making mistakes. Miss and it's automatic damage for you. Then you have to cancel his fireball attack by typing 3 phrases in a short timespan before they hit you, and only then can you do damage to him.
The vampire from Severance: Blade of Darkness. A lot of HP, powerfull attacks, drains your life, teleports behind you and has a strong shield that deals massive damage to you if you hit. And you WILL hit it, since he has his guard raised most of the time. And you fight this bastard several times. If you go back to previous levels for 100% Completion by collecting every Plot Coupon to unlock the Sword Beam on the Infinity+1 Sword he pops up as a Boss In Mooks Clothing several more times, with less health but still holding that frigging shield (which you never get to pick up).
Moles the walrus from Billy Hatcher and the Giant Egg, he first starts by ice skidding towards you which is easy to doge but then he rolls into a sphere of ice, and very rapidly starts bouncing around the room, and this attack is very unpredictable, also to make matter worse every time he hits a wall, small ice spheres appear and start bouncing around the room with him, eventually he will stop and allow you to hurt him but those ice spheres are still bouncing around, and while you're focusing on hurting him, those ice spheres can hit you, stunning you for a second, and he will repeat this process for the whole fight.
Dark Corvo is even worse, he uses shadow clones of previous bosses that you have fought, some of his attacks are extremely hard to dodge, for example his shadow clone of Glur shoots homing bouncy balls, his Saltim clone rapid fires bombs at you, which are a very hard to dodge, also when Dark Corvo clones himself and attacks you, he attacks at high speed, and there is no clue as to which is the real one, and if you don't hit the right one fast enough he will repeat the attack, it is especially painful that Dark Corvo comes after one of the hardest levels in the game. He's so hard that the game actually warns you how hard he's gonna be before you fight him, and this is a hard game!
While Marvel Ultimate Alliance is fairly easy, the Mandarin is an incredibly tedious and irksome boss fight. He spends most of the fight in secret rooms you have to access via teleporter. The problem is if you use the teleporter, the Ultimo will follow you in and pull you back out. The way to override this to get one of the exploding bugs into the teleporter with Ultimo so it explodes on him which is... difficult.
Frogger Beyond has some fairly difficult bosses, but the Claw note Think a demonic, oversized disembodied skill crane completely stops the game right then and there. The battle consists of pressing buttons 1 to 4 in order, while avoiding its fireballs. Sounds easy? Not one bit. The first phase is so easy it's not even funny. Then comes the second phase, which is a huge leap in difficulty. Not only are the switches out of order, but there's a lot of missing spaces and moving platforms. Its attack is firing a row of fireballs in a single line, which can easily hit Frogger if the fireballs are in the line of a moving platform. The third phase? It's a borderline Luck-Based Mission. The buttons are not only out of order, but constantly move, there's less actual space and more moving platforms, and the claw gains a nigh-unavoidable cluster of fireballs that is extremely difficult to dodge. It's also full of Fake Difficulty because you most likely don't get a chance to analyze its pattern at all before being hit. Oh yeah, Frogger has one hit point, so get hit once and it's back to the beginning. If there's one good thing about the boss, it won't attack when Frogger is on a moving platform.
Nowhere near as frustrating as the Claw, but still difficult, is the tank boss in World 4. It's surrounded by four spiked shields, so you obviously have to remove them. How? With a bit of the old Misguided Missile strategy. Unfortunately, the shield power units are guarded by pillars of ice that are quite difficult to work around, and are put up randomly. And it's all compounded by the fact that it's typically shooting lots of mortars at you before it decides to shoot a missile. And when you finally remove all the shields, you not only have to deal with the mortars and keep directing the missile, you also have to deal with the tank moving around, trying to run you over! And the target is the tank itself this time, so good luck trying to get it. And just like before, getting hit just once starts the whole nonsense over.
The Octopus in World 2 is a massive Difficulty Spike from the previous one. You're moving around a circular arena trying to dodge its tentacles, which sometimes move around, slap the ground, or alternate between being raised and on the ground. It only can be harmed when these floating exploding barrels appear and you have to navigate them and hit the switch... and then return before it explodes. The more hits it takes, the barrels require more difficult and quick platforming to get through or risk not making it back in time... and there's only three of them, so you have to deal with crossing its arms to reach all of them. Get hit? You know what happens.
The fight with Tyrant on board the plane in Resident Evil: Code: Veronica. As usual, it's Made of Iron and a Lightning Bruiser, but this time, there's hardly any room to maneuver. There is also an element of Puzzle Boss where you have to use the catapult to throw it out of the plane after weakening it with your weapons, if it's not damaged enough, it will throw the crate back at you.
In the NES adaptation ofWillow, you have General Kael. If you try attacking him from the sides, he'll charge at you, dealing significant amounts of damage. Attacking him from the front leaves you open to his sword, also dealing a lot of damage. Standing still will have his sword deflected off of your shield; using that technique is crucial to survive the fight.
The first Pac-Man World game brings us Anubis Rex and the King Galaxian.
The first phase of Anubis's fight, which takes place in a small corridor where he chases Pac-Man from a first-person perspective, isn't terribly difficult (although it's very easy to run over a spear). Once you exit the corridor, however, your ass is grass. You have to damage him by first exposing its heart by using rev-roll switches placed above lava that shoots fireballs. The first time you hit him, he starts hurling miniature tornadoes at you, which requires precise butt bouncing. The second time you hit him, fireballs start dropping out of the sky and land on the rev-roll platforms, requiring you to jump and start over with activating the switch. The third time has him fire a laser from his forehead, which has a very wide hitbox and requires even more impeccable timing than the tornado. But here's the kicker: none of the projectiles go away when the next one activates. This means that during the final phase, you have to stand still and activate each switch, which takes five seconds each, all while avoiding a small tornado, a gigantic laser, and about fifty dozen flaming rocks jumping at you, all at the same time. And we might as well mention that Anubis Rex is the second boss of the game.
King Galaxian, while not nearly as annoying as Anubis Rex, is still pretty bad. First off, Unexpected Shmup Level. Second, before you even fight him, you have to survive a level, filled with King Galaxian's drones, an asteroid field, and a giant battleship. Third, there is exactly one easy-to-miss checkpoint halfway through the level. Finally, the boss himself is no slouch either, requiring you to dodge dozens of photon shots and drones before you can take out his eyes.
And then there's Blinky (called Clyde since Pac-Man Arrangement) in Pac Man World 2. His fight is almost exactly the same as the two before him, but there are a few minor differences that will make you screw up big time, the first of which is him being able to place flames on the ground with his fireballs and his ramming attack. The biggest problem with this is that the flames are practically invisible. You have to squint really hard in order to make them out, and there's likely to be at least seven or eight of them on the platform at once. Next, the speed at which he spits fireballs at you is just stupid fast. Unless you have split-second reflexes, prepare to get shot plenty of times. Did we mention that he can stunlock you to death with the fireballs if they connect at the right moment? As an added bonus, Blinky's machine can't be damaged by rev-rolls like the last two; you HAVE to wait until he comes down and butt-bash the glass cockpit. Cue Rage Quit at the next corner...
The final boss, Greedy, from Ristar. Let's check his three forms shall we?
At first, he refuses to even fight you, throwing up five, newly introduced and unique to this fight, teleporting mooks, which move in random directions and fire energy weapons in your general direction. They also move REALLY quickly. If the Random Number God is not in your favour today, this sequence alone can be an absolute nightmare.
After a few hits, Greedy stops messing around, and the real fun starts. In his third form, he can now summon black holes, and fry the floor with lightning. Oh. And he's even quicker than before. Getting through this fight unscathed without Pause Scumming is a considerable feat.
inFAMOUS has Kessler. While he IS the final boss, he reaches ridiculous levels of difficulty when playing on hard (for more reasons than just the difficulty being raised in general). His health is absolutely ridiculous (to the point where it has a checkpoint every 25%, and it can take nearly an hour to whittle him down all the way), and he dodges everything. Grenade hits are pure luck, and not consistent enough to be worth it. He automatically dodges missiles (your second most damaging attack, and best hope of killing him),and will charge you (followed immediately by killing you) if you try to get him with your Storm (though it can be used at one point in the fight when he summons drones. This is the only way to not die). So, you can only hit him with your basic lightning bolt. Bad enough as is. Add in the fact that he has SEVERAL attacks that will kill you instantly if you don't have full health or dodge, and a charging attack that allows him to evade your shots while rushing at you for an impressive swing.
King Fury in Ōkamiden. The first problem: he flies, so it can be difficult to hit him with a normal attack. Second: he's absurdly fast. Third: your partner has to spend most of the fight standing in front of a control panel and King Fury apparently knows he can only take 3 hits, because he specifically targets him over Chibi, turning the fight into an Escort Mission as well. But the biggest problem? Ink no longer regenerates. You have to counter almost every move King Fury makes with one or two brush techniques, and if you're lucky, you can hit him maybe once or twice every time you knock him down. This means it takes a lot of ink to do a little damage, so you'll probably run out of Spirit Ink before long. And then you get him down to half hitpoints, and he summons a clone.
Viewtiful Joe had Another Joe. An awesome boss in his own right, he has a knack for killing you without breaking a sweat. One of his attacks can decimate your health if you're unprepared for it, and if you run out of VFX while fending it off, your death is guaranteed. Made doubly frustrating as you end up having to fight him a second time at the end of a mandatory Boss Rush.
Fire Leo was the final boss at the end of the Boss Rush. His battle involved you using a shitload of Mach Speed to set YOURSELF on fire so you were immune to his fireballs (temporarily), rushing after the free-running bastard and pummeling him until he either jumped back into the lava surrounding the platform, or he decided to do his ridiculous ballerina twirl claw attack. Said attack gives you ''very little warning'' before he strikes (on harder difficulties, you get no warning whatsoever). Also, he runs around the platforms spewing giant rocks that will hurt and temporarily stun you if they land on you. The same rocks you have to punch to avoid being set on fire.
The Stage 24 boss in Bleach: Soul Carnival 2, a pair of Menos Grande. One of them will invariably teleport right on top of you at the start of the fight, and getting hit by these guys sends you flying. It doesn't help that half the ground you can fight these behemoths on is quicksand, which does damage if you're stuck in it long enough. Additionally, your regular attacks do naught but 1 point of damage to them, forcing you to rely on special attacks. And if you get caught in between them while they Beam Spam, but can't hit both of them at once? Time to start over.
Before them, however, there's Hollow Ichigo in Stage 21. Hollow Ichigo is fast and can do anything you can do...with one exception: He can use a Burning Attack and you can't. One that takes up the screen and deals an ungodly amount of damage.
Speaking of Dual Bosses, there's Ikkaku and Renji at the end of the first Challenge stage. If Ikkaku's long spear combos don't drive you up the wall, then Renji's homing sword-things will. And if that doesn't get you? They will invariably activate Bankai, sometimes simultaneously. In this state, their attacks get ridiculous range and priority, and a Burning Attack won't stagger them. It does damage, sure, but it doesn't stop their relentless assault.
The Cores and Turrets Boss in Stage 3 of Journey To Silius fires a complex pattern of lasers and bullets, making it much more difficult than other bosses, since you have to jump through the hail of fire to hit the core, and you are probably low on gun power at this point.
The Final Boss is much easier to beat if you're not going for 100% Completion. If you are, then you don't get to use the special item that calls a meteor down upon Datatshushi to kill it off. You can only use it twice, and must use a special sword to finish the battle. Unfortunately, being the type of game that it is, melee combat is very awkward, and since the Final Boss flies above you at all times, you have to aim up to hit it with the sword. This battle seems to take forever; it's possible that enemies regenerate health in this game.
Takeuchi's interminable fight against Shibito Akira. It's an incredibly long and difficult duel between Takeuchi, who only has a pistol, and Akira, who has a rifle. It takes place on a small battlefield where you can mercifully take cover if you need to regenerate your health.
The Surpreme Hunter (the second time you fight him from Prototype, especially on Hard. For starters, he has a truly ridiculous amount of health, so much health that the game hands you tons of 500 pound bombs and aircraft to throw at him, and it still barely hurts him. Rocket launchers and helicopter missiles are next to useless against him, but apparently no one told the soldiers on the USS Reagan, because the entire time you're fighting him there are explosions slamming into both of you. He can take it fine, whereas you get knocked around and have huge amounts of your health taken off. The boss's attacks are all extremely damaging, and at least one of them is unblockable. However, the worst part is the time limit, which is ridiculously strict. You have to execute everything perfectly to defeat the boss in the tiny amount of time you're given. If you are hit by two rockets or one of the boss's attacks over the course of the fight, you may as well start the fight over, since you just wasted too much getting up from the knockback animation and your character (along with New York City) is now a nuclear crater.
Chairman Drek from the first game is infamous for how hard he is. Many people say they had to buy the BFG of the game series, the RYNO, to beat him without losing their sanity.
He gets a bit easier when you know that you can upgrade your weaker weapons to gold weapons before you finished the game, which falls under Guide Dang It . Especialy the golden suck cannon is a god send, since it allows to take out all his minions and use them as projectiles against him.
Dr. Nefarious in the third game can be a real challenge the first few times around, especially if you haven't leveled up your weapons enough.
Luna in Size Matters is ridiculous. The battle starts off with a "run towards the camera while dodging the rocks and were-sheep" section that seems to last forever. Then, when you actually get to the battle, she will promptly run you over and spam rockets, and her vehicle has a ton of health. And every time you lose, it's right back through the running section.
KLUNK in Secret Agent Clank's Challenge Mode. He can kill you in 4 hits, your weapons do barely any damage to him whatsoever even as Level 4 Proto Weapons, and every time you die you have to start from scratch. Even the Dallas Chalice won't help you much, since you can only use it once during the fight.
Verdugo in Resident Evil 4; it is Tyrant hybridized with the Predator. Extremely fast, damaging, and nigh invulnerable when not frozen by liquid nitrogen, and its attacks must be dodged in quick time events most of the time. There's only four LN 2 canisters to freeze him, so don't waste them. Luckily, if you saved the freebie rocket launcher from earlier, you can One-Hit Kill him.
Onimusha: Dawn of Dreams brings us Sakon. He actually gets easy the second and third times you fight him, but the first time is one of the most annoying battles in the game. The cell you're in is rather small and being near Sakon is enough to get you killed thanks to his monster aura. Doesn't help his sword as a massively unfair range. If you can't go Oni and get caught, you are going to be destroyed, hard.
The cheapest is Monsoon, a good example of what happens when you combine a boss that was already a Lightning Bruiser and an invulnerability mode that you have to block the attacks of in order to even get a shot at. Oh yeah, and did we mention he's a master of long range and has a Teleport Spam attack?
The only saving grace is that one of Monsoon's attacks drops medkits. And he tends to use it when you're running low on medkits.
The Final Boss is nothing but pain and torment. He has difficult-to-avoid attacks that absolutely wreck Raiden even at full health, a few long-range attacks that are all different, but come out the same. He has twice as much health as every other boss in the game and is only vulnerable when he's setting up an attack. He has a painful grabbing attack that leaves Raiden vulnerable, and can chuck pieces of debris that must be sliced precisely or say good bye to 70% of your health. and the best part? No checkpoints. Also, none of this guy's attacks can be parried; even on the Easy mode with auto parries, you can barely deflect 10% of this guy's attacks. It's even worse when Playing Sam's DLC: With Raiden, he has the speed and essentially being able to continue his combo non-stop that a seasoned player can learn to handle the Final Boss with relative ease. With Sam, you have dodge and counter. The worst part? The Final Boss is far more aggressive and has new beefed up attacks that are unblock-able. Worse still is that Sam's parry requires stricter timing than Raiden's, meaning that if the player had trouble with parrying in the main game, Sam's DLC would be a nightmare.
The first boss, because it requires more thought and variety in strategy than every other boss prior to the fourth once, so it acts as an incredibly brutal Wake-Up Call Boss. The annoying spiders don't help matters.
The fourth boss (Shrewd/Scornful Possessor). Not only does the battle use different gameplay mechanics than every other boss battle in the game, but you have both a limited amount of ammo and the annoyance of the boss regenerating health to boot. And if your vehicle overheats (like if the boss hits it during its one true attack) its an instant game over. And prior to this point you've never had any practice with the shooting mechanics at all. It's bad enough a significant amount of players have practically given up on the game because of it. Also, you have two ways to aim. You can either use the circle pad, or tilt the 3DS. However, the tilting control is inaccurate, so you need to use the circle pad. It might seem like it's not a problem, until you discover you can't turn off the tilting controls, so you will have to set your 3DS on a surface in case you want to use the pad.
The fifth world boss, Ambush Manuever, may also qualify. BigBoo is fought in a similar manner to Boolossus in the first game. He is composed of small Boos and has 2 attacks which, due to his humoungous size, can be quite difficult to dodge. To actually beat it, you have to wait until he uses one. If he slams the ground, he will eventually get dizzy and you need to perform a power surge on his tongue to send him in front of the train. However, more likely than not he will be in an area that doesn't have enough room to perform one (To do a power surge, you need to pull it's tongue in any direction). If it dives into the ground, it will charge into you. If it hits other parts of the train, it will simply get dizzy, giving you a free hit. If you manage to send it in FRONT of the train, it will then split up into smaller ones. (Think about an orange on a squeezer.) You then need to send every single one of the 8 Boos into cages using the same tactic from the former attack. Luckily for you, said cages are conveniently attached to the train. Also, if you send a Boo into a cage that already has one inside, it will simply bounce off it. And every attack, even from the smaller ones deal 20 damage and that the train is constantly moving. If can't get the timing right, this boss will be your nightmare.
Freedom Planet's Lord Brevon is considered ridiculously hard, even by Final Boss standards. He moves quickly, throws out attacks with great rapidity, and has an attack that can shave off half of your health that comes out with little warning (this makes fighting him with Milla a nightmare, since she has less health than Lilac or Carol).
Magicka's Grimnir is hands-down the hardest boss in the game. Before you even fight him, you have to go through the Mind Duel, in which he pits you up against at least one of every enemy spellcaster in the game, in a tiny arena surrounded by a bottomless pit, with no time to recover in between. When the real battle starts, you're fighting on a tiny spit of land surrounded by another bottomless pit, with the confined space making it even easier than normal to hurt your friends at inopportune times, and VERY hard to dodge his attacks. He can shield himself, create an unkillable Ethereal duplicate that will mercilessly bombard you with projectile Spells, and can cast powerful Magicks including Rain (weakens Fire and makes it suicidal to use Lightning), Tornado (very hard to avoid, sends you off the edge if you go near it), and Conflagration (nearly impossible to avoid, deals ludicrous damage, sets you on fire, making you take damage over time and sometimes causing your character to panic and, more often than not, run off the edge). If you fall of the edge you lose any items you were carrying, so if you're going for a Dragon Slayerrun, good luck holding on to Gram. Oh, and you have to fight him twice, the second time without the Mind Duel but with the ability to summon two duplicates rather than just one.
The three Necromancers halfway through Chapter 9 are That One Miniboss, being harder than a lot of the "real" bosses. They're already accompanied by Wights, which are tough on their own, but will also be constantly summoning Zombies to create a massive horde of minions that will flood the screen within a minute. The real problem is that Life Spells hurt the Zombies but heal the Necromancers, so it's impossible to fight both at the same time. Your best (read: only) bet is to chuck Earth/Ice projectiles at the Necromancers as early and as often as possible and hope for the best.
The final boss, Assatur, definitely counts. You fight him immediately after two other boss fights, and when I say "immediately" I mean "if you don't cast a complicated Magick within a few seconds at the end of the second boss fight, he'll heal the boss back to full health and make you fight him again". If you do actually get to the final battle, you'll find that he's huge, immobile, defenceless, and only has a few attacks. But of the more powerful of those attacks, one is nearly impossible to avoid unless you stand in EXACTLY the right place and does massive damage, one causes extremely damaging explosions in completely random locations, and one appears instantly in the middle of the arena, instantly kills you if you're not far enough away, and can easily wipe out your group in seconds. This guy just doesn't know the meaning of the word "fair".
Magicka: The Stars Are Left is specifically meant to be harder than the original game, to the point where all of the bosses count as this to some degree:
Parker is constantly spawning annoying minions, is hard to get close to, and her web attack will paralyse and subsequently insta-kill you unless you burn your way out very quickly.
Dagon will never ever stop chasing you. If he gets close to you, he hits HARD, so you'll usually be to busy running away to actually attack him. He also has one nasty attack which is hard to see coming and will almost always kill you instantly. The kicker? You have to fight him THREE TIMES.
Cthulhu, however, blows all the other examples from the game out of the water. Yes, even Grimnir. You have a tiny space in which to fight him (as usual, going of the edge kills you), and most of the time you can't even get close to the edge of the top half without getting pulled off by his tentacles. He can hit you from any angle, summon minions, has an attack that will instantly kill you if you're in front of him and don't react very quickly. To top it off, halfway through the fight he drops Dagon in to the arena, making you fight TWO BOSSES AT ONCE.
Claw is a fairly challenging game in its own right, so it's only natural that certain bosses encountered prove a pain to deal with.
Wolvington, third boss of the game. You have likely a split second to move towards him before he starts throwing magic bullets at you, stripping you off 15 health a hit. You have 100 at max. He throws up to six bullets, so do the math. Even when you do manage to corner him he counters every hit with an upper. Think you can just crouch-slash your way through the fight? Have a sword. New versions of the game Nerfed his magic blasts to more reasonable 5 health per hit.
Gabriel that comes after Wolvington is a seemingly straightforward Puzzle Boss: you have to use his cannon against him to damage him. What's the catch? Well, he throws bombs like crazy. As if the sole fact that the tiles you need to climb on to even reach the button disappear after a second or so, if he hits you, you're down 15 health and stun-locked in the air. If, God forbid, he wallops you with all three of those, well, have fun. Oh, and he periodically summons Red Tail Pirates to bother you. There's an exploit you can use to reach him instantly and end a fight in a flash, but then you miss out on all the treasure beforehand. Pick your poison.
Marrow: to reach him you have to hit his parrot a couple of times to open yourself a path and not get impaled on One-Hit Kill spikes. Too bad that the parrot comes out so fast you have to react immediately to not get hit. Marrow himself also takes potshots at you with his pistol while you're struggling to avoid both. And when you finally reach him if you're not swift enough there's a chance he'll just gut you like a fish with his sword.
Red Tail, the penultimate boss. Compared to others he has no fancy gimmick apart from his Western Winds, but you won't have a good time regardless. If you drop off the ledge for even a moment he'll blow you right into spikes and even then you have to watch out for throwing daggers, pistol shots and slides. Add to the fact that you can only hit him twice before he hops back to safety and that he's got health to spare and you're in for a frustrating slugfest.
While Omar is a Final Boss, he gained enough notoriety among the fanbase to qualify as TOB. The first phase of this fight has you jumping through a variety of traps and pitfalls to reach a power-up necessary to damage him... and even once you have it, you still need to go back and hit him through a small hole in his fire/ice shield, effectively giving you something like ten-fifteen seconds. You have to do it three more times before you can take an elevator to the second phase of the fight and now Omar is serious. You have to reach him through a course of Bottomless Pits where a single hit will stun-lock you mid-air and most likely throw you into the lava. Before he was Nerfed, you needed to hit him twelve times. At least he was forgiving enough to not make you repeat both phases of the fight.