Negative mouse acceleration, for example in Metal Gear Rising. Wanted to play the game again several times, but only imagining how tedious camera controls were, and those are needed for efficient battle control, keeps me from even bothering with it. Since then games that use this feature have a hard time getting on my wishlist.

You can pretty much say the same about any game that is a cut version.
Skyrim has the same level scaling problem, right?

Not ruining it, but i am disappointed and annoyed as I am playing now Zelda Breath of the Wild (Wii U) there is no recipe list of cooked meals / created potions in the game... Except making a meal / elixir and keeping it in bag "for the record" to ever access the recipe in the menu (instead of eating, drinking it...) there is no practical way to remember what ingredients are needed / used for what result, beside keeping a pen & paper, notepad open...

This is not cool as it is an integral part of the game, this search for effective survival means (resist cold / heat, temporary stamina, health boost...) through experimenting with the cooking pot to create or reproduce elixirs, dishes... Very strange this is missing in such a big game and i seem to be one of the very few struck by this problem in my first hours in, I certainly did not read about it in any of the many professional and user reviews online, not even once outside actually searching for casual posts addressing the issue like mine here...

I wish a future update will bring that important feature sometime later... Hopefully please, a recipe list!! (Or, maybe Ignis spoiled me...)

I play mostly RPGs, and game is ruined for me if it has limited in-game resources, for example: no monster respawn, time limit, etc. Level-scaling is part of it too, because it limits your character progression (or, in other words, completely removes the whole point of leveling up). Examples are too many in modern PC games....

"No monster respawn" is especially game-breaking for me if game features random loot.
I can read "Final Fantasy IX" in highlighted sentence. Also, 12 hours limit to get one of the best weapons in the game...

Actually, when it comes to the FF series, it's actually Final Fantasy 6 which I think of first, with its esper level up bonuses. (FF6 and FF9 share another flaw: The ATB doesn't stop during battle animations, resulting in situations where lots of actions are queued up, leading me to (on wait mode) open a sub-menu so that actions can resolve while time is still running.)

Incidentally, Dragon Quest 3 (original) has an issue regarding HP/MP gains that ruins that game for me. Your HP/MP can only increase when your Vit/Int increases at level up, and there's a finite limit to how high those stats can go. Even worse, if you use a seed to boost one of those stats, you have permanently reduced the amount of HP/MP the character can gain. While there's a seed-like item to fix HP, there isn't one for MP. Fortunately, the remakes fixed this issue.

By the way, what's your opinion on the Morrowind/Oblivion leveling system? (Ignore level scaling when answering this question.)

That mention of Ultima Underworld reminds me of one other example:

Ultima 4-7: The need for reagents to cast spells.

But also, there's more:

Ultima 5: The Shadowlord's appearance in town. To level up, in addition to getting enough EXP, you *also* need to get lucky while resting for Lord British to appear. Also, level ups only give +1 to a random stat, and there's no other infinite way to raise your stats (and the finite way only works for the main character).

Ultima 6: Navigating from point A to point B without using the red moonstone is a pain.

Ultima 7: Real time combat ruined this game. Also, the need to manually feed your characters is also a huge step back, especially since you need to look through your inventory (in a game with a horrible inventory system) for a food item to use. (Even reagents aren't this bad because you don't actually need to find them in your inventory to use them.)

Serpent Isle: You don't get the spellbook until well into the game. Given that spell casting is the only interesting thing you can do in combat, this ruins the early part of the game. (At least, if you have the expansion, you can get a ring that eliminates the need for reagents once you do finally get the spellbook.)

Ultima 8: No female character option (when every earlier game in the series allowed one).

No idea, haven't played it yet.

The first two Turok games on the N64, some control oddities and the HORRENDOUS framerate in the second game even in Low Res mode. I am thankful for Night Dive's remasters of the games because they are much more playable than the original N64 versions.

The lack of narration in the Dark Souls series. To me 'narration' adds to 'motivation', one of the crucial factors that makes me want to finish a game, especially in games that feel rather repetitive. In a game that is 80 hours long I want to have an actual reason for doing things, apart from it just being there. In shorter games I'm fine with this shallow set-up, but not in lengthier games, as I eventually get bored and quit the game.

Forza 4 (-6) and Shift 1+ 2. In racing games that claim to be sim-like I find it overly annoying to have AI drivers behave like teenage online gamers or attention-seeking YouTube/Twitch mororns. I eventually loose interest in playing these kind of racing games.

Brutal Legend, the RTS stuff. It's the one single thing that keeps me from buying and replaying the game. Can't somone mod that thing out leave the rest of the game intact ?

Too Human. That 30-second unskippable cutscene each time you die. The game was fun otherwise, but this is a game where you can die very quickly. I have been tempted to try the game again though, because it is very unique.

Darwinia. The AI is overbearingly dumb. It was fine babysitting them in the first part of the game, but as more is required of them it just got far too frustrating towards the end... the bad type of frustrating.

Star Wars Dark Forces. The first-person platforming. This is one of those rare cases where I think using a gamepad for platforming is a better idea. So if I ever replay the game it will be with a gamepad.

Dead State. The morale system made no sense at all in this game, and you could very loose the game because you did not find enough luxury goods for your people even though they had plenty of regular food ... not to mention safety and water. I used a console cheat to more or less disable the morale system and that was indeed the right choice, it's a great game without it. So to me cheats can be used to actually make a game better, more fun.

I picked up Fable 2 due to the hype. I soon realized how easy the game was and when I asked around, it turns out there is no difficulty setting and the whole game is a cakewalk since Molyneux was clearly more focused on emotes and job minigames. I wanted an RPG with a challenge, not The Sims. In general, games are marred if you never have to put in any effort into progressing. It cheapens everything. When you have to struggle to make progress, when you spend some time overcoming a tough challenge, you appreciate the new content you're unlocked that much more. But that's just my jaded 20-year-long-gamer self taking. I used to cheat my butt off in games when I started out. So I would have enjoyed Fable when I was, like, 12.

Baldur's Gate - level cap
Star Wars Battlefront 2 - horrible campaign
M.A.X. - turn limits
Divinity 2: enemy experience decrease by increasing level
Rise of the Triad (both versions) - jump & run elements
Drox Operative - skill points spent in command useless until reaching limit for new ship

Metal gear Solid V phantom pain - FOB component. Just another way to pump the money from players and cripple gameplay.

Europa Universalis IV - Corruption system

Resident evil revelation 2 - Bad gameplay.

Incubation - Difficulty of areas.

Tyranny - Short RPG game

Diablo 3 -Console-like game mechanics.

Resident evil 6 -Not survival horror game

No, Ignis didn't spoil you. The game honestly needs a lot of QoL features, and that does include showing what you have made with things so you don't end up selling all your sapphires so you can't make (hypothetical) Sapphire Armor.
More games need to have a slider like Bravely Default so you can control the encounter rate. Like, if there's one feature I'd force onto Pokemon, it would be trainer evading (I don't want to battle right now) and better repel.

If to ignore level-up requirements, level-up bonus calculation and some other similar flaws, I actually liked it. I also liked the variation of this system in EverQuest and in Might and Magic VI+.