Thankfully, X and Y's Victory Road isn't too bad. If you pace yourself and plan your steps right, you can avoid a good amount of the trainers if you choose and the caves aren't too hard to navigate, even without a guidebook.
One of the annoying bits of Pokémon is that the Fire starter tends to have lots of problems in its path - the Water Gym, the Rock Gym (hi Brock and Roxanne, That One Boss) all do double damage to it and have your strongest moves halved or negated. Also, the early areas are either devoid of Water-Types or have Water-Types that need a bit of training before they can do well. There are three solutions. Get a Magikarp, level it up to a Gyarados, and give it some Water move. Get a Geodude/Diglett and let it learn Earthquake or Magnitude, which are super effective against Rock-types. Or, majorly level up your Fire Pokémon until it can take out every enemy in one hit (or teach it SolarBeam if it is compatible with the move).
This is fixed in the Black/White games, where the first two gyms ensure that you have the same advantage no matter what your starter is. Which is to say that no matter who you pick, you will be at a disadvantage in the first gym — that's why you receive the Elemental Monkey in the Dreamyard.
Fixed even further in Black and White 2, where the first Leader is Normal-type. Though the fact he has a Lillipup and a Patrat sort of make it pointlessly easy anyway. However, they can utilize the move Work Up to increase their Attack, and the Lillipup is particularly fast and likely to get in a hit. It can sweep your party if you don't have an adequately prepared team.
Not quite levels, but the Battle Frontier and Safari Zone could definitely count. The Safari Zone cranks the Luck-Based Mission aspect of catching them allUp to Eleven, and you'll easily spend quite a bit of time there trying to catch a specific Mon (it's worse in HGSS thanks to the objects system). And the Battle Frontier pretty much puts up Help Wanted ads that say "If you're a God-damned cheating bastard, come sign up for the Battle Tower/Hall/etc. challenges today!" And it's not bad enough that the Frontier is a difficult challenge on its own: it's actually vital to spend hours upon hours grinding up BP (Frontier currency) for the good items, especially the ones required to evolve certain Pokémon.
In every game with BP it is possible to get one of almost all the rare evolution items through fully exploring each area.
In Heart Gold and Soul Silver: Those helpful Move Tutors that you had to work for but not too hard in the past games? Yeah, you need BP in order for your Pokémon to learn moves from them, too. You need to go through several cheating battles many times over before you have enough money to teach your bugs how to bite things.
Gen I and Remakes
Seafoam Islands in Red/Blue/Yellow. If you want to catch the legendary Articuno, you have to travel through the underground caves. However, Articuno is located in a part of the caves only accessible by Surfing on water where the current is extremely fast, so you can't Surf normally until you use Strength to drop boulders through holes into the water, which will change its flow and slow the current.
Another contender is Rock Tunnel in FireRed and LeafGreen. You need to go through it to get Flash, and it's full of Com Mons like Geodude and Zubats. It's just a minor thing, but it's a maelstrom of Goddamned Bats. Not only that, but it's much, MUCH bigger in the remakes than it was in the original.
In addition, it contains Ditto, which is a pain in the ass to capture in order to fill your Pokedex unless you put it to sleep on the first turn thanks to Transform.
Gen II and Remakes
The Ice Path from Pokémon Gold and Silver and remakes is another one, between the ice sliding and pushing boullders through holes and more ice...
Mt. Mortar in Gold/Silver. It's the largest cave in the entire series, it's basically an enormous maze, it's pitch-black inside, it has countless Strength puzzles, and, to top it all off, it has the highest possible Pokémon encounter rate, so when you inevitably get lost you'll spend five times as long getting out as you would otherwise. Thankfully, it was made a little easier in Crystal and the Video Game Remake, but it's still rather annoying.
What's especially annoying is the whole point of going into Mt. Mortar is to get a rare Pokémon, and if you have all six party spots full you have to leave, ditch the extra Pokémon, then go through it again. But the game doesn't tell you that until you actually get to the character who gives it to you. In fact, the game doesn't even tell you that you'll get a rare Pokémon by entering the mountain.
Fortunately, you can also get that rare Pokémon by trading a Hitmonchan or Hitmonlee from R/B/Y and breeding it with a Ditto.
Johto Route 40-41 in Pokémon Gold and Silver can also be a contender. Most likely, it's the first time you'll be sailing/surfing on your Pokémon, as Cianwood City Gym would be your next gym after Ecruteak. On your way, you'll be facing Tentacools and Tentacruels. Problem is, due to their dual-water/poison type, and their moves, your Pokemon will probably be poisoned, requiring lots of antidotes and/or potions. They are the only ones you'll be facing, and due to the nature of water terrain, you'll probably end up encountering more often. Repels may not necessarily work either, as there are Tentacruels which can go up to level 29, which is rather high for this stage in the game. note For reference, all of the swimmers' trainer battles on the way are mostly around 18-23. Eusine's Pokemon in the Cianwood City event battle is around 25 at the most. Chuck's Pokémon for the gym battle are 27-31. And this is in addition to any trainer battles you make along the way. At least, once you beat Chuck, you'll now have the option to fly straight back to Olivine City.
Mt. Silver from HGSS is a major competitor too. It got a major revamp from the original version and is quite long, and requires Rock Climb to ascend—which means the game forces you to face the True Final Boss with an HM Slave in your party, or waste one of your mainstay's move slots with it.
Though at least Rock Climb isn't a completely atrocious move—for an HM, anyway—it's got fairly decent attack and can cause opponents to become confused.
Gen III and Remakes
What about the one Trick House in Gen III with all the arrow floors that only let you go one way? Thank God it's optional. (Liza and Tate's Gym, which has similar floors, is almost as tough.)
Worse yet is the setup with the barriers that rotate every time you pass through them, which are used in Winona's Gym as well.
Sky Pillar in Pokemon Ruby And Sapphire. You have to use the Mach Bike and do everything exactly right in regards to speed and sharp turns to get across the floor before you fall through it. In Emerald, you have to do it to progress the storyline, because you need to wake up Rayquaza to calm Kyogre and Groudon. However, the floor isn't so bad then. It's only after Rayquaza flies out and destroys the place that you have a problem. Then you have to do it all over again later to catch the darn thing. On top of that, the resident Claydol are tanks and are just waiting to explode in your face. (The Banette, Altaria and Sableye aren't terrible, really, though Sableye isn't weak to anything you throw at it and is immune to Normal, Psychic, and Fighting-type attacks. Banette is also invulnerable to Normal and Fighting attacks but still has weaknesses.) Just bring lots of repel unless you're out to catch one.
Mirage Tower has a similar setup with trying to get across the cracked floor, though it's not as big as Sky Pillar and there are just a lot of Trapinch and Sandshrew in there, nothing serious.
The cracked floor in Dewford Cave is also very annoying, especially since you have fairly narrow areas to steer through. Thankfully, this part of the cave is completely optional (and, if it's the first time you've played the game, you might not even think to go back there).
Also from Gen III is the water route where the sunken area for the Regi sidequest is at. You have to watch the currents and try not to miss the small square, or fly back to Pacifidlog Town and do it all over again. Getting to all the trainers and items on the route is just as big a pain.
Wallace's cracked ice gym puzzle. Step on the same tile twice and you fall through the floor. You also have to step on every tile at least once before it will let you move on. Even if you completed the puzzle, it won't stay solved until after you've climbed up the steps.
Candice's Gym is just ridiculous. It's a big icy pit where you have to slide down towards the center while building up enough momentum to smash through the snowballs at the bottom. But there are trainers, snow patches, and stairs positioned just right to prevent you from just, y'know, sliding down normally; instead you have to circle around the gym finding the most obtuse paths possible to get enough momentum. It's not unknown for first-time players to spend up to an hour solving this puzzle.
Worse is the route (and part of Mt. Coronet) in fourth generation that features fog. Fog that lowers your accuracy, making your Pokémon miss nearly every single time but has almost no effect on your opponent. Add to this the fact that Defog is just about the most useless HM ever (and only Pokémon with wings can learn it, preventing you from giving it to a common Pokémon like Bibarel).
Another from the Gen. IV: the muddy terrain around Pastoria and inside the Great Marsh. There's a good chance of getting stuck when walking into a marsh tile, in which case the player must press different directional buttons repeatedly to become unstuck. This has to be done at practically every single step. As if that wasn't excruciatingly slow enough, each of those little wiggles to free oneself can result in a wild Pokémon encounter.
Stare closely at the screen and you can see that the sticky tiles are slightly darker than the ones that aren't. Nintendo always makes this trick in Pokémon games, like Koga's invisible wall Gym.
This was made far more obvious for the Platinum release as well.
Gen IV also gave us routes 216 and 217, especially 217. Lots of ice types, long distances, perpetual hail, the necessity of pushing through Mt Coronet to even get there, and in the case of 217, a straightforward blizzard that makes it virtually impossible to see what you're doing or where you're going beyond "Snowpoint is up". Then, just for giggles, remember that the first two games in this series had only one Fire type that could be caught in the wild prior to completing the main game.
Victory Road, while not difficult to complete (and actually rather simple if you're not interested in all the trainers and items), requires Surf, Waterfall, Rock Smash, Strength and Rock Climb. If you want to complete the post-game section with Marley, you're probably bringing Defog as well.
Pinwheel Forest in Black and White. The sign outside more or less says "Pinwheel Forest: Hope you remembered some Antidote."
Chargestone Cave. The wild 'Mons are annoyingly tough (Boldore has a Last Chance Hit Point ability but thankfully can't explode at the levels it's found here; Joltik can prevent you from using Berry items and can slow you down with Electroweb; Klink are Steel-type and will whack you with Gear Grind, which hits twice; Ferroseed, which on top of being a Stone Wall with only two weaknesses has an ability that costs you health every time you hit it; and Nosepass in the sequels, which is even more of a Stone Wall, also has Sturdy, and prevents fleeing if the active 'Mon is a Steel-type). While most of them are slow enough that running away is easy, there will be a lot of encounters, and they will get very annoying very quickly. The cave is long and packed with Trainers. Also, the Doctor trainer is located somewhat off the beaten path. At least he's right before the start of the Team Plasma gauntlet, making healing much more convenient.
The worst part, for Hundred Percent Completionists looking to complete the Pokedex, is Tynamo. There is a 1 in 50 chance of this mon appearing (unless you go to the bottom floor, in which case it's 1 in 12, but of course going to the bottom floor is quite annoying in itself). Even going through the entire dungeon, it's quite possible to never see a single one, meaning you will have to stay there for quite a while searching. And Tynamo has very poor defenses, so unless you brought False Swipe, good luck weakening it without killing it. Granted, Tynamo eventually evolves into the devastatingly strongEelektross, so the difficulty was probably intentional.
The World Tournament can turn into this, because you cannot predict which gym leaders you'll face and it's hard to get type coverage for everything out of just three Pokémon.
One of the worst in the region leader tourmanents, though, is the Kanto Leaders tournament. If you want to access all the other tournaments, you have to beat the first five regions' leaders, which turns them into brick walls. The worst part is that the Gen I (and the cross-generational evolutions of them) mons they use are strong. Very strong. Lt. Surge's Electrode, Giovanni's Rhyperior, Misty's Starmie... They're all very nasty. And conveniently hold items that dampen your attacks or boost their one stat/move you were trying to use to get through them/don't want to be hit with. Yeesh.
The less said about the Champions' Tournament... the better.
The Mix/Mix Master Tournaments, which are similar to the rest of the tournaments... but the twist is, a random mon of your team and the opponent's team is switched. Your Game Breaker isn't so awesome when it's going against you, huh? Plus, you have to figure out how to work with the mon you received, which is a challenge in and of itself. A fun challenge, but still brutal.
Black Tower/White Treehollow. The first half is fine, but after Area 5, all the areas have multiple floors for you to search through to find the gate boss. And you can't use items from your bag (though your Pokemon can hold berries or herbs or battle items). There are nurses scattered about, but remembering where they are can be tricky. Also, by the end, everyone's using level 70 and above Pokemon, including the Legendary Bird trio. Since we all know The Computer Is a Cheating Bastard, look out for their OHKO moves like Articuno's Sheer Cold.
Thankfully though, there are no level and olympus mon limits placed on the player, meaning that it is all fine and dandy to unleash your level 100 Zekrom upon the unsuspecting trainers in the area.
Though the general bulk of the main game is light on these areas, one very tricky area is Victory Road. Unlike the ones in the previous games, this Victory Road is different from any you've seen. The trainers there use Pokémon at Levels 54 and 55 (and on Challenge Mode, 58 and 59), which is higher than the levels Ghetsis and Colress had in the Plasma Frigate that you just harrowed through. And nearly all of them, especially Veterans and Ace Trainers, have very odd movesets on their Pokémon that often provide wide type coverage and can sneak up on you if you're not prepared for them. In addition, there are seven different areas that you can catch wild Pokémon in, and types including Ghost, Grass, Flying, Rock, Water, Fighting, Ground, Rock and Dragon. And in the thick grass they come out at Level 52-55, which tops at one level below what the Elite Four's lowest are. To put that in perspective, you could catch yourself at least half a team's worth and use that against the Elite Four. Finally, you have to fight your rival at the very end, and he only has four Pokémon, but they're quite powerful, especially Bouffalant, his new addition to his team, which is quite bulky and can hit very hard with moves like Head Charge and Earthquake. This place may honestly be just as hard as the Elite Four and Champion themselves. The only thing that keeps it from being any worse is that there's a Doctor not far in who will heal your Pokémon free of charge if you can beat his Clefable (that likes to be stupid with Minimize), and if you're deep in, it might be an unpleasant walk back to him unless you have Fly to return to the entrance.
The Dream Radar. Nintendo lured people to plunk down money/trade in their old DS systems by making the game a DS game but the radar 3DS. Once you get it, you battle mons by chasing them with a Ray Gun, wishing they'd stay still because you have about 90 secs to zap them enough to catch them or they flee. It's nice when you get enough dream orbs to get the extensions that freeze 'em for a few seconds, makes your beam stronger and increases your time. Especially since every zap you get from a mon cuts your time. Oh and some mons, like Swablu,port and zip all over and are a pain to catch. Also annoying when what you get from all that isn't a mon but an item. And for the three legends, you need lots of patience. Tornadus comes at 400 orbs, which comes fast. But Thundurus comes at 1500 orbs and Landorus at 3000. By then, you'll be bored with the regular mons because you catch several of a few, like Munna, Swablu, Drifloon and Riolu. More come out with each genie you catch but you're still going to end up with a lot of repeats by the end.
Those points outlined are not even the worst parts of it. The worst part about the dream radar is how it handles saves and sending pokemon. When you send a pokemon through dream radar to Black and white 2 in such a way soft resting is impossible. And you can only send one each legendary per save file on both games. Resetting Black and white 2 is easy and you can get to the point where transfer is possible in only a few minutes of play, but Dream Radar? I hope you like going through the whole thing again. Oh, and as an added bonus, once you get to the point where transfer is possible, Nintendo anticipated the possibility of you trying to back it up, so that means if you want to back up your data, you have to manually delete the software to get that backup file and then transfer it over to some other medium, because it will automatically be deleted when you reinstall the software.
Match 14 of the Battle Subway, on the regular lines. Before, you've been fighting unevolved Pokémon with a few singly-evolved ones and maybe a couple of weaker fully-evolved ones. Suddenly, the Trainers start throwing the Elemental Monkeys and Basculin at you, and pack other strong fully-evolved mons. Considering this is right at the end of a good winning streak, it hurts even more to lose. Then if you somehow win, you have to go through even more of Trainers like these.
Then once you somehow beat the Subway Boss, you unlock the Super ___ Train, which consists of nothing but fully-evolved Pokémon from all generations.
While it's a bit strange for a city to be this, Lumiose City in Pokémon X and Y is easily one of the most hated areas of the game. Absurdly awkward camera angles make it nigh-impossible to see any of where you're going, the circular design makes all of the features seemingly blend into each other, there are basically no landmarks apart from the central tower, and everything looks almost exactly the same. Finding anything in the city is an exercise in frustration, looking around seemingly everywhere without any hints whatsoever, and it's entirely possible to walk right by it without even noticing due to the camera angle. If you want access to the boutique, you need to visit every single place in the city - Last Lousy Point doesn't even begin to describe it. Sometimes, it's easy to wind up in the wrong building, especially through the error of slightly nudging yourself into the wrong door. And if all of this wasn't enough, there was a Game-Breaking Bug (now with available patch) where if you saved outside in the wrong place, it can permanently freeze your game and was hard to fix, as described here.
The Post-Game has you going back and forth all over the city looking for lost Pokemon, thieves, and the like hidden all over the place. There are at three tricky to find alleys that you have to backtrack to multiple times, which you cannot Taxi to.
Laverre Gym. It's another teleporter maze. In addition, the gym's specialty type is brand-new, so new players may not know how to deal with the Pokémon the trainers and Valerie have, and are decently high-leveled.
Route 20, or the Winding Woods as it's also referred to as. It's another forest, and when you go forward, should you attempt to go back through the same entrance, chances are you can end up in a completely different part of the forest from where you came in. This can make attempting to find certain parts of the area frustrating. What's even worse is that it's a pretty good location to grind your team in...if you don't mind all of the wild Level 50 Amoonguss that like to spam Solar Beam and Synthesis, and can status you with Effect Spore should you use contact moves against them.
Route 13 is this in SPADES. On the plus side, there are no random encounters. However, they're replaced by digging Pokémon that move in erratic fashions,follow you relentlessly and are immune to repels. Combine that with an easterly wind that slows you down to a crawl (regardless if you walk, run, or use the Roller Skates or Bicycle), and those diggers are nigh unavoidable. And for navigation...well, it's not bad if you're just traveling between Coumarine City and Lumiose City. But have fun finding the Kalos Power Plant, and may Arceus help you if you're brave (or foolish) enough to go hunting for items. And that's not all — it's the only place in the entire game where you can evolve Magneton and Nosepass, so if you want Magnezone and/or Probopass on your team or just want to complete your Pokédex, you'll HAVE to return. At least one player has wondered why the Kalos government hasn't just carpet-bombed the entire route.
What doesn't make things any better is that the encounters are mostly Dugtrio and Trapinch, both of which sport the infamous Arena Trap ability. Better lead with a Ghost-type or a Flying-type when going through the route. Or catch a Pokémon that has the "Run Away" ability.
The Reflection Cave. Good god, the Reflection Cave. It's the first cave with random encounters that you face (The Glittering Cave has a certain amount of wild Pokemon that are scripted to come out). The mirrors make it very hard to see where you're going, there are a ton of dead ends, and the worse part is you can find wild WOBBUFFET here. All Wobbuffet have the ability Shadow Tag, which prevents you from fleeing the battle or even swapping out. It's also incredibly defensive, which means it can easily survive the attacks you have to use to finish the battle and it knows both Counter and Mirror Coat which can reflect your attacks back for DOUBLE DAMAGE. If you run into a wild Wobbuffet, expect to lose at least one Pokemon to it. And did I mention there are still trainers to fight? This place can become a nightmare.
The scrappy level for Red/Blue Rescue Team would be Purity Forest. It's 99 floors long, you can only bring one Pokémon, said Pokémon is reduced to level 1, and all of your money and toolbox contents are destroyed. You're pretty much at the random generator's mercy here.
While not as bad, there's also Western Cave. 99 floors, no food items not in Kecleon Shops, and Tyranitars swarm the middle floors and activate Sand Stream. This dungeon will throw everything at you, including the kitchen sink, if you aren't high leveled. And your reward for making it to the last of those 99 floors? Mewtwo (who should be a complete joke compared to some of the bosses you've faced, especially after making it past those previous 98 floors. Also, he won't join you the first time. That's right, you have to go through the cave a SECOND time to recruit him. But on the plus side, the wild foes give LOTS of EXP points. Expect to gain at least ten levels per one go through to the end.
In the main story mode, Sky Tower can be a tough climb. Early floors have you dealing with ghosts, who can travel through walls and attack your Pokémon there, while most Pokémon cannot attack into walls. There are also floors that activate different weather, including Hail, which drains your health faster than you can heal it off, forcing you to scramble for the exit. Enemies also start getting nastier, featuring lots of enemies with the PP-draining Pressure ability, foes like Venomoth who use Silver Wind to hit anyone in the same room as it, and Aerodactyl, who can use not only Supersonic to confuse you, but also Agility to make all the enemy Pokémon in the same room move at double speed. And in these later levels, it isn't uncommon to stumble into a Monster House, which dumps ten or so Pokémon at you all at once. Arceus help you if two or more Aerodactyl drop in, as their combined Agility will mean you'll be ganged up on all sides by Pokémon moving at quadruple speed while Venomoth in the back spam Silver Wind on your team. The only saving grace is that its layouts are simple, unlike Magma Cavern.
Aegis Cave in Pokémon Mystery DungeonExplorers of Time/Darkness. It's not a hard dungeon— there are ample oran berries and the Unown aren't that tough at all. But you have to find stones that Unown drop, of their own letter-shape, to spell out I-C-E, R-O-C-K, and S-T-E-E-L. Not every type appears, and even then, the stones are dropped maybe a quarter of the time. And you have to keep repeating a three-floor section until you get all the letters you need so you can go on and fight the appropriate Legendary Golem (who, thankfully, aren't that tough). And did I mention you can't save in between, so you HAVE to do this all in one go? Fortunately, much of the annoyance can be simplified, thanks to an inherent quirk of the Legendary Golems. Simply put, bring a Fighting type.
Explorers of Sky brought us the ultimate dungeon: Destiny Tower. Like Purity Forest, it has 99 floors, you're only allowed to bring in your leader and its level will be lowered to 1, and you're not allowed to bring in any items or money. It also prevents you from using your IQ skills note which keeps Reviver Seeds from activating thanks to no Item Master, and keeps traps hidden when you step on them. Worst part? Some of these traps are absolute cruelty, with the worst one being the "Grudge" trap, which gives a PERMANENT grudge status to EVERY SINGLE POKÉMON ON THE FLOOR. And for the icing on the cake, you can't be rescued, so if you're knocked out even one time, you have to start all over again. Good luck getting to the top.
Likewise, Sky has Zero Isle Center. Foes begin at Level 90 and quickly make their way to Level 99 but give no EXP Points whatsoever. Similarly to Destiny Tower, traps only become visible when you step on them, Grudge Traps which give never-ending Grudge status to every Pokemon on the floor, lots of traps and frequent monster houses, only being allowed to bring 16 items, and some randomly placed Level 5 Pokemon like Clefairy and Togepi on some floors.
Dark Crater. Just when it seems that everything's going fine, suddenly something screws up by either Cresselia failing somewhere, or one of your teammates getting hit by an overpowered move (multi-hit moves say hello!). At this rate, Reviver Seeds are important, but suddenly there is none of these for a lot of levels.
Dark Hill is this if you are a Normal-type Pokémon, as your normal-type moves do only 1/4 damage to ghosts, which comprise the majority of the Pokémon there. Plus, several Pokémon have Spite, which will remove all of the PP of the move last used, just in case you have any dark-type moves. Finally, Dusclops know the move Curse, which is nigh impossible to survive without an Oran Berry. Did we mention this place has 15 floors?
The Great Glacier (first visit) in Gates to Infinity. It's especially brutal for being right in the mid-game. First off, it's got 14 floors. Second, some floors have Hail active, which not only disables passive healing but does slight but steady damage over time, and nobody you have is immune to it. Third, you're stuck with a limited selection of party members, one of which isn't very strong (and newly-recruited members are sent right off to Paradise, so no additional team building). Fourth, if the hail wasn't bad enough, the place is infested with Yamask and Trubbish, which will burn and poison your team, sapping their health even more (and poison disables passive healing even on the floors without Hail). Trubbish is especially bad, as it's got lots of health and it can prevent you from attacking if you hit it. And finally, it's right after a 10-floor dungeon (Telluric Path) filled with more annoying enemies. To make things worse, you can't leave the dungeon at any time. You better pray you find a Pure Seed (which warps you to the stairs) for those Hail floors...
Not long afterwards is the Forest of Shadows, for several reasons. What's the biggest? MONSTER HOUSES. This is the first dungeon that includes Monster Houses, and they're quite brutal. End up wandering into a room full of treasure and you're assaulted by 10 or so strong Pokemon at once while an Archeops in the back spams Agility (double speed for everyone!) There's also a good chance you'll step on a trap when you immediately enter; if it's a Sleep trap, you're screwed. If you don't have any Petrify or Sleep Orbs on you, you're good as dead unless you can pull off a Team Attack right then and there. And if you're really unlucky, it's possible that the only way through a dungeon is through a Monster House. It's also a 14-floor dungeon with weather effects, though thankfully it's only Rain. Still disables passive healing and weakens Tepig's more powerful moves, but at least it doesn't damage you like Hail. You also can only take two party members: yourself and your partner. The local mons are quite annoying: Vaporeon has lots of health and will spam Sand-Attack, Tail Whip, and Aurora Beam (which can lower your attack), and are immune to Water-type attacks. Druddigon are quite strong and can randomly hurt you when you hit them. Archeops are thankfully sleeping outside Monster Houses but are so powerful they need the Defeatist Ability. Conkeldurr is very strong and can boost its Attack if burned or poisoned. It's also right at the beginning of a long gauntlet of dungeons (although you can switch to Companion Mode to have them obtain items if needed).
Withering Savanna. Good news: you picked up a level 64 Hydreigon from the last dungeon! Bad news: this dungeon is full of Lilligant that spam Teeter Dance (which confuses the entire room.) Your ally isn't so useful when he can't even hit anything - or you can't hit anything, for that matter. It's also a 17-floor dungeon. Of course, have the Prevention Team Skill, or a couple of Persim Bands, and you're fine.
Escorting the bug-phobic mechanic in the first Pokemon Ranger game. He freaked out and made you start over if he - or YOU, for some unfathomable reason - touched so much as a single bug. Oh, and you have to escort him through the most bug-infested area of the game, with loads who will either just float around randomly but quickly, or CHASE AFTER YOU - many of the latter being FASTER THAN YOU ARE.
That one temple where you have to first fight a Kingdra, Charizard and Flygon and then use Pokémon to get through an irritating maze and THEN fight a Salamence at the end without saving. It's a complete Luck-Based Mission, because you can't use your Plusle— even though Salamence isn't immune to electricity.
Hippowdon Temple in the second game. The constant, damage-inducing sand balls were downright obnoxious. It doesn't help that all that hard work goes to waste since you lose the Yellow Gem to Heath.
The second time you go through Boyle Volcano is a real pain in the butt. You got lava geysers spraying up from the ground, and Hot Boulders flying around as if launched from invisible cannons. Then there's the tendency of EVERY Pokémon to have some way to attack you and send you flying. And then, if you survive, you have to go up against Lavana and her Infernape, and then HEATRANnote Think you can you use your brandy Shieldon or nearby Rhydon to stop him from attacking? Nope, Heatran will still summon these lava pools..
In the third game, Mt. Sorbet. Most of the level is fine, but then you get to the part with the avalanches. Every few seconds, there is a long drawn-out cutscene where an avalanche happens. You have to be behind a big pillar to shield yourself from the avalanche, or you'll be back at the bottom. The game is picky about whether you're behind it or not. It doesn't help that the game slows you down in these areas. And there are two of these areas. And you will probably come back to that area again. Also, Mt. Layuda, specifically the parts where all the agitated Electric Pokémon are attacking you so you fall into the pits and also a section similar to Mt. Sorbet where you have to cross a pool of water that is constantly being electrified by lightning and if you're not standing on one of the patches of land you'll get electrocuted and take damage.
Empoleon's Snow Slide in PokéPark Wii, especially when you're trying to get all the bonuses by beating the required time limits. Your worst enemy isn't another Pokemon, but rather the wall. That's right, walls are your worst enemy in this minigame. They slow you down, you will always hit them when you make a turn (Yes, even if you slow yourself down deliberately beforehand), and they are everywhere. It's especially bad when you're using a particularly fast Pokemon such as Empoleon or Glaceon, who seem to be magnetically attracted to hit every single wall in existence.
The "Obstacle Hop" skill game in which you befriend Machamp. Remember how easy the first one was with Spearow? Well, welcome to Pokemon's version of Platform Hell. Complete with bad camera angles, surprisingly difficult jumps, and Machamp hurling boulders at you that are impossible to dodge.
The Lava Zone has one notorious side-quest that's both frustrating and difficult. Long story short, you have to bring some iron ore (that you get via drill) down to where Camerupt is so that you can use it to make a new lever for the furnace (the old one broke). However, not only do you have to deal with the shoddy camera angles in the game (causing you to get stuck in areas that you think you can walk on), but you also have to deal with Torkoal. A lot of Torkoal. Alotofvery angry Torkoal that will constantly ram into you causing you to drop the iron you need to fix the furnace and advance in the game. Did we mention that any time you carry an item, you move at about one-fourth of your normal speed, you can't dash, and you are unable to use Thunderbolt? Good luck getting past all those angry Torkoal.
Oh, and did we mention that the Torkoal will chase you all the way to where Camerupt is and will still ram into you afterwards?
Granite Zone has a particularly annoying area where you have to step on a switch and jump across timed platforms in order to progress in the game. The problem lies in the game's poor camera angle and controls. You cannot just dash across, or you'll fall, and you have to move quickly while jumping or else the platforms will disappear. In other words, have fun doing the same part over and over again.
In Pokémon Battle Revolution, Sunset Colosseum. During the actual game, it's a rental matchup, with you and your opponent choosing four Pokémon from a pool of 12. It's hard to predict your opponent's choices and you may not always have the moves to beat them. The Colosseum boss usually uses Vigoroth, with Body Slam and Brick Break, and Gible with Dragon Rush. Then there's his Grovyle with Leaf Blade. And if you choose Gible, look out for Luxio with Ice Fang. Then, once you beat the game, this level turns into a several set survival challenge without a guarantee of healing at the end like usual. You spin a wheel that tells you if you'll get PP restored, HP restored, items restored,ect.
If you thought you would sweep the game by bringing a team of ridiculously powerful Pokémon... welcome to Neon Colosseum. The Pokémon are randomly chosen from both your team and your opponent's team... Which means, more often than not, you will end up with your opponent's crappy Pokémon and your opponent will get your Olympus Mons. Good luck.
The higher ranks of the Colosseum games, (Rank 8, Level 50), where everyone uses legendaries.
Pokédex 3D Pro has various daily quizzes, and they range from simple (name the given Pokémon from, say, the Johto region) to tough (name the given Pokémon's Egg Group). But if you happen to find one about learnable moves, prepare to tear your hair out. There are many questions, and they are incredibly difficult. Some make sense (Arcanine can't learn Water Gun, silly), some are a given (Double Team, Protect, Rest, Toxic, etc. can be learned by nearly everyone) some require more thinking (that blade-slinging Pokémon could probably learn False Swipe or Slash...), but some just don't make sense at first. Normal-types are major offenders. And then there's tutor moves, TMs, and of course, Egg Moves. The quiz also loves to throw you off (which move can this Pokémon not learn?). It's a long, frustrating, luck-based mess, especially for the perfectionists.
Really want to get frustrated? A multiple choice quiz to name a Pokémon solely on its cry. And you have to complete it with no mistakes as fast as humanly possible if you want that gold trophy.
One quiz requires you to name Unown by their appearance. Sounds pretty easy, right? They're only the letters of the English alphabet, after all. Too bad the time limit for one particular quiz is insanely short. It doesn't help that some of the Unown aren't exactly clear, either.
One type of Daily Challenge can pit you against the entire Pokédex. That's right, you have to endure 649 questions in a row without making any errors. Just the normal "what Pokémon is this" quiz is brutal enough, but get something like Peek 2 (black screen with a tiny hole moving around that reveals the Pokémon) or Learnable Moves and you'd be better off skipping that day.
Aqua Dome. You're only a fifth of the way through the game and are thrown a tricky water level. Here, you're having to deal with underwater tunnels and mazes filled with enemies, but on top of that, you also have to climb up skeletal structures, make you way over areas of rushing water, where falling in is fatal, ride water slides in a cavern area where once again falling is fatal, and go through a frigid glacier area with ultracold water where falling into it is once again fatal! You also have to climb up a waterfall over a bottomless pit, raise the water level in a room while dealing with an increasing number of enemies, and ride a hydro jet in order to progress. On top of all that, you have to deal with large bubble enemies that shoot damaging bubbles, missiles, or lasers at you and fight two midbosses (3 if you're using Duplica). And when all that's said and done, you need to run through a crushing waterfall area before dealing with Archie, then make your way through one last area with a short time limit while making sure you don't awaken Kyogre. Mess up at any one of these points and it's back to the beginning for you!
Flora Cave can be considered even trickier than Aqua Dome since you're having to deal with tougher enemies as well as hazards such as vines the burst out of nowhere, turning what look like simple areas into mazes, flower platforms that snap shut periodically and damage you if they do, as well as pools of poison water that kills you instantly! There's one area where you make your way through treetops and if you fall, not only do you land on damaging brambles, but you have to go back and repeat the section. Then there's the killer plants, which drop down from nowhere and immediately attack you, flowers that shoot lasers that tend to be in areas where you're not looking, and giant Venus flytraps that if you don't scurry across quickly, they'll snap shut on you! If you're going for score, do not attack the female Team Flora Grunts (which don't attack), since you'll actually lose points if you do. There's also the matter of escorting Celebi later on in the stage and you can't have its HP be reduced to 0 as well as an area with rising poison water. Finally, two (three if you're Duplica) midbosses must be taken down along the way as well as Farlie at the end, who turns out to be a difficult puzzle boss. Only then can you breathe easy.
This stage is even worse if you're playing the Special Mission Mode or the Ultra difficulty (as well as the rerelease of this stage in Chaos Adventure), since the female Grunts actually attack this time, requiring you to dispose of them as well.