The Hitchhiker's Guide to the Galaxy is the text-based puzzle equivalent of Platform Hell. The mere mention of the phrase "Babel fish" can be enough to make grown men crynote If you fix the Babel fish dispenser as each test fails then you will just barely run out of attempts, so the only way to succeed is by psychic foreknowledge. On top of that, the methods needed to fix it are mostly nonsensical. One of them requires an inconspicuous pile of mail that was on your doorstep at the beginning on the game. If you forgot to grab it, you could spend hours trying to figure out why you can't solve the puzzle..
The game has a late puzzle where you need to use one item out of a pool of 10+ items. The game is specifically coded to always pick one you don't have (and likely can't get anymore) if possible.
Riven is usually regarded as the hardest game in the already difficult Myst franchise. Unlike the other games, Riven consists of minor puzzles spread out over a very large area. These combine into the two major puzzles of the game, which have ten bazillion possible combinations (the "waffle iron" and "animal stone" puzzle). Also, the clues to the puzzles are often integrated into the puzzles themselves, rather than being signposted as clues. Even still, Riven is still regarded by some as the best game in the series.
Shadowgate. Dear God, Shadowgate. Have fun with a first-person point-and-click adventure-type game with even more random instant deaths ("you take a look at the scroll, only to find out it's a scroll of explode and kill whoever tries to read it, nyah nyah") than NetHack, and sometimes the right answer is fairly obscure.
There is one room of the game with three mirrors. The only way to proceed is by smashing one of them with a sledgehammer to reveal a door that you open and go through. However, another one apparently has a magical black hole or something behind it as smashing it reveals a vortex that sucks you in to your death, and the third just has a wall, but trying to smash it somehow leads you to breaking it in such a way that the flying shards kill you. Hope you saved before having to take a complete unaided wild guess as to which one's which... And that's one of the easier puzzles.
One room has a pit with an obvious ladder affixed to one side. I hope you're not dumb enough to think that means you can climb down and that they won't just reveal afterwards that the ladder only goes down about an inch past what you can see from the top and then suddenly stops, leading you to fall to your death. Obviously the answer is to only come back much, much later, when you have a spell that can make ropes levitate.
Did we mention your character will sometimes gleefully commit suicide if you so much as click on the wrong part of a room map or use certain items in your inventory in the wrong way?
The Swedish translation of the game (a rare occurrence in those days) makes things worse by mistranslating one of the objects needed to kill the final boss. The only way to figure it out is by trial and error.
Actually made even harder by Nintendo Power. The room where you collect the staff has a rickety bridge where you fall into a bottomless pit when you try to cross. The solution in their walkthrough was so wrong that many who played it on the Game Boy Color for the first time were completely stumped by it. They recommend dropping all your items, which the game won't let you do in that room. (This is the solution in the PC versions of the game, but the inventory system was changed in the NES and GBC versions so as to render this method useless. Instead you have to drink a potion - unlabeled, naturally - that makes you lighter, allowing you to cross.)
Uninvited was MUCH worse than Shadowgate. In the start of the game, there's a hallway where a mysterious woman appears that is actually a ghost and will kill you. The only way to beat her is to enter one specific upstairs room first and find something called "No Ghost" to use on her. Oh, and you have to OPEN the No Ghost before using it or it won't work; your character will just approach the ghost, shake a capped bottle at it, and get the hell killed out of himself. It just gets worse from there.
In a game like this, a huge ruby sounds like a totally awesome thing that you will need later, so of course you take it. Several minutes later, more than long enough to forget about it in the midst of avoiding all the OTHER death lurking about the place, you get a few cryptic messages about slowly having your consciousness encroached upon by a strange force. Then you die. The game never explains that the ruby in your inventory is the source of the possession, and if you choose to restart after dying of it, you will still have it.
This only applies to the NES version. In all other versions, this happens whether you have the ruby or not (although it takes much longer for the game to kill you in all other versions).
There's also the literal Ghost Butler upstairs. To defeat him, you need to use spray adhesive on an outdoor railing and trap a spider that walks by. Then, you use something called "Spider Cider" to knock out the tiny arachnid and take it with you. Then, you throw that little spider at the butler, scaring him and making him disappear. Some players may have figured out how to catch the spider without looking it up, but it's impossible to guess where to use it because there's no indication anywhere in the game that the butler is afraid of spiders. None.
At the very least, Shadowgate gave clues stating that the Staff of Ages, Golden Blade, Silver Orb, Bladed Sun Talisman and Platinum Horn were they keys to beating the Big Bad. No such clues were given as to how to finish Uninvited. So of course you would just figure out that you're supposed to turn on a bathtub to flood a bathroom and float up to the hatch above (disguised as a light fixture, natch), then hit your sister to release the demon inside her, THEN kill the demon with holy water from a goblet that you took from a church much earlier in the game!!!
And Déjà Vu is no better, simply put. Improper usage of any item in ICOM's adventure games is a game over.
In fact, it adds its own little twist. Some of the items you get are needed to prove your innocence. Others are the planted evidence against you. You'll need to figure out which is which, and discard the latter in the sewer. Miss one of the plants, and you'll get a nice shiny set of silver bracelets. Granted, the game is slightly less difficult to figure out compared to Shadowgate and Uninvited, since it mostly plays by real-world logic, but careful observation of your items and surroundings is still mandatory.
Double Switch. Think of the game as Night Trap, but with the difficulty cranked Up to Eleven. For starters, this game has no timer, so you will have a hard time knowing just when an enemy shows up so you can trap him. You have to be careful not to let too many enemies escape, or it's Game Over. Some of them are top priority, because they will attempt to cut off your connection to the security system, and if they do that, it's Game Over. Some of them will try to kill the tenants of the apartment building, so you will have to trap them, or it's Game Over. As the game goes on, you will have to quickly switch between screens, and timing becomes vital. There is one point in the game where you will be given a trap, and you actually have to be at that screen to be told about it - while simultaneously saving a tenant's live in another screen. You need that trap, or it will be Game Over later on. There are points where have to keep traps disarmed and then quickly arm them again. Failure to do so results in Game Over. Yes, timing becomes increasingly important as the game goes on, and you will have to activate traps at some rather precise moments. Welcome to Nintendo Hard!
King's Quest III is perhaps not as unfair as V overall, but the first half of the game puts you on a strict 20-minute cycling time limit, with the possibility of death if you're caught holding any particular items or not in the right place when the time is up (with a long and itself dangerous mountain path between the region you need to explore and the "safe zone" to boot!). Of course, leaving not much room for uninhibited exploring or experimenting in a game like this imposes a huge challenge if you're coming in blind. Plus there's a notorious Copy Protection puzzle where you have to input spells directly from the manual. One typo will mean your doom. Fan remakes and the AGD expanded version make these aspects of the game easier.
King's Quest V. The game is rife with dead ends, pixel hunts, rooms you cannot return to, and pixel hunts in a room you cannot return to avoid a dead end later. If you didn't notice an item earlier, you'll get stuck and have no way of knowing what you're missing and where from. Very few puzzles in the game make any logical sense, and then there's Cedric the owl...
Wizards and Warriors. More specifically, the sequel. While you are not technically a One-Hit-Point Wonder, as you have a life meter, many enemies (if not the majority of them) can one-hit kill you, especially in the later levels. Your main (and often your only) weapon is a sword that has such ridiculously short range it's practically impossible to hit anything without getting hit yourself. Oh, and you only get two continues.
Dear God, Jurassic Park on SNES. It was the game's lack of a save feature that made it the grueling challenge it was. With a limited amount of extra lives to obtain, making mistakes were not only usually fatal, but would also bring you that much closer to losing all of your progress. The game was fairly big too, hiding raptor eggs all over the map, and featuring several multi-layered buildings. And if you found a locked door, it usually meant trekking across the treacherous island to another building to find the key card for that door.
You didn't think a Visual Novel would end up here do you? However, the Dating SimSummer Session manages to do just that. It takes place in a high school/college setting and you have to get 1 of 5 girls and pass the final exam. This is easier said than done. The game requires you to balance your schedule to raise your stats and pass your exams. However, you need to shy away from this routine to meet the girls, you also need to work to earn money and such. However there is a stress bar that can make you fail your actions if high enough, and you need almost max intelligence to pass the final exam, and you only gain 2-4 intelligence per day if you choose to study, making it very hard to build up relationships with a girl and get an ending. Also, you can actually fail the final exam and get the bad ending even if you're smart enough if the stress meter was too high. Furthermore, building the right relationships with the girls can be a major Guide Dang It!.
The dadaist anti-gameTakeshi no Chosenjou (translated as Takeshi's Challenge) features all of the stuff that makes adventure games hard to play and cranks it Up to Eleven. There are nearly infinite paths you can take in the game but only 2 of them will get you to be able to see the ending. The requirements by themselves are also very obscure (one moment you have an option menu, you can only continue if you select the first option and wait 15-30 minutes before you press A to continue (not sooner nor later) or the second option after which you have to wait for an hour or more before you can press A to continue playing). The game has been considered impossible to play without a guide or walkthrough. There were hints given in the 2 adverts for the game as well so that you know how to beat it but even those hints were rather obscure as well.
YU-NO has a time traveling mechanism which allows you to instantly hop between distant parts of the storyline branches, letting you carry items between unrelated scenes. There's a catch, however: you can only travel to moments where you've "dropped" beforehand a "save-jewel", a magical jewel. There's a limited amount of these, 8 in the PC-98 and Windows versions and 10 in the Sega Saturn and remake versions. This system is in place of a conventional save-load system. The timeline is extremely complex, with dozens of confusing branches, loops and U-turns, and some of the routes require items from the end of another route. It's important to leave jewels in important moments so you can return to them later. "Loading" a dropped jewel also automatically puts it back into your pocket, so you may have to remember to instantly drop it again to keep the moment easily accessible. Furthermore, to view the in-game map which you use for loading jewel-saves, you must have at least one unused jewel in your possession. Screw up, and you may have to replay a significant chunk of the game.