I don't like durability mechanics when its clearly there just to waste your time or money or whatever. Any game that makes you do more hiking to repair benches than fighting is either getting a thumbs down or I'm going to download a mod.

Escort missions. Specifically when the person you are escorting is as sharp as a bag of hammers.

Not a mechanic i guess, but motion blur

QTE, especially when they're randomly inserted into an otherwise action/skill based game.

Very few checkpoints or save options. I don’t have time to try to beat something if there is like 20 mins of playtime from the last checkpoint.

Game has collectables scattered in almost every room including lore text and audio logs.

Meanwhile the story NPC is nagging you to move on every 30 seconds on a loop and won't shut the fuck up. Because play testing revealed most of their players are fucking morons and get lost in one way apartment rooms I guess.

These two mechanics conflct with one another way too often and it's immersion breaking every time.

Both Control and the dogshit Avengers game had these upgrade systems where you were constantly bombarded with pickups that offered inane benefits like “2.5% increase to headshot damage for 3 seconds after taking damage while in midair” and you spent half the game managing your goddamn upgrades and the limited upgrade slots instead of having fun. It got to the point where I was relieved when I DIDN’T get any upgrades after a battle.

I don't think that I can give the worst, but I can give some that I did not enjoy.

• Invisible teleporters. Some old RPGs

like the D&D Gold Box games

came without an auto-mapping feature. Part of the game was, as one played along, manually creating a map on graph paper. This in-and-of-itself was somewhat time-consuming, and if one made a mistake or got turned around, it could be hard to fix one's map. A particularly obnoxious feature to complicate this was that sometimes, there'd be unmarked teleporters to move you to another place on the map without notice, and you had to figure out that this had happened. Very annoying. I didn't like this mechanic.

• Real-time games with an intentional omission of a pause feature. Some strategy games do this. The idea here is to force you to think in real time, and not permit you to just pause and think about things. Problem is, even if one agrees with this, in the real world, sometimes you need to answer the door or use the toilet. Not a good idea.

• In general, positive-feedback loops that increase the difficulty for the player. An example would be shmups where being hit causes not just the loss of a life, but the loss of a level of one's precious weapon power, or something like that. That means that when one is doing poorly, the difficulty also ramps up. There's some degree of this in many games insofar as it might be harder to play when one is weaker, but in the shmup case, I really don't think that it's necessary

a game would be perfectly playable without that element. I don't really like situations where it's just added for the sake of being there.

Where one enemy sees you and now all their friends somehow knows where you are

Insert real world money to continue/for advantage. Whether it's modern FTP with MTX or old school quarter eaters, it's poison to games.

Not really a game mechanic, but as an achievement hunter I freakin' HATE speedrun-achievements. The longer the game, the worse it is

Unskippable intro levels that teach the control mechanics.

Time gates. Gacha games are rife with them...

Want a piece of equipment for your character? Well spend daily currency to get one that regenerates over a day. Oops rng God hates you and you got +Def for a character that wants +Atk, better luck tomorrow/next week... Oops it's still not your week +Hp this time.

Stat/EXP loss on death.

Unskippable cut scenes, especially before a boss. I want to play on hard difficulty, which means I WILL die to bosses. Do not force me to watch that shit 5+ times or I'm out like trout.

Probably encumberance, almost certainly the single most ignored rule in rpgs.

But honorable mention goes to old school AC/THAC0 - the mechanics were originally for modern-era battleship game where armor class referred to size. Using the smallness of boats to model the defensive power of better armor was never going to produce sensible results. THAC0 was always unweildy at the table, slowed play, and turned combat into a chorus of "uggghhhh does a 13 hit?" "Ugh.... no."

QTE, including those i have to align those bar that goes left and right, or those tap a button quickly, in any game that isn't point and click adventure game. It's not fun in God of War, and it's not fun in Dying Light.

Also extreme hand-holding tutorial that force you to click button or do certain action else your progression is refused. This happened a lot in mobile game, which i basically refuse to play.

Capitalism, as seen in monopoly

The worst game mechanic is artificial difficulty where enemies aren't challenging. Instead, they are just damage sponges.

Alien pods getting a free move as soon as you uncover them

Time limits / countdowns.

Microtransactions - the answer always has been and always will be microtransactions.

Games with inventories where they treat a single gem or a flower petal as occupying the same space in your rucksack as a pair of boots.

Guys, we go back to Ultima 7 with the key ring, the problem was solved along fucking time ago. Stop being lazy and have gem sacks, crafting bags, keyrings, etc for small items.

Been playing Dark Deity (a Fire Emblem clone) lately and instead of permadeath, it reduces a random stat by 10% permanently. Can't say I'm a fan. Just have a permadeath mode and a regular mode.

multiplayer shooters with unlockable weapons/classes

Often it's climbing.

I'm looking at you, breath of the wild.

Doom3 flashlight. It’s Doom. Not fucking 5 Nights at Freddy’s.

Microtransactions

Escort missions

The only good escort missions are the ones where you aren't limited at all by the NPC you need to escort, which no longer makes it an escort mission.

Holding a button to do anything/everything. I can see the logic of where it may be useful, but it doesn't need to be used for everything. So damn annoying.

*Oh, and similarly, forcing excessive submenus to do basic things, like continue a save from the main menu. That should be one, maybe two button presses, not 4+ along with a confirmation. I'll never understand games with stuff like that.

Ah another one - Forced stealth sections where you can't be detected at all. Especially in a game where stealth is optional or not even a thing you can really do normally.

Taking control away from the player for stupid bullshit.

Dragon's Dogma 2 had this to the most extreme level I had ever seen. Random NPCs can initiate dialogue without you hitting a prompt (and they can appear anywhere, even in the middle of a cave full of monsters). Your companions will sometimes high five you, and it just forces you into an animation that it didn't prompt you for. There is an actual boss fight in the game that is literally a cutscene of someone else fighting it.

Dragon's Dogma? More like Dragon's Dogshit. 😬

Not really the worst, but my hot take of something I don't like: puzzles rather than problems. By that I mean puzzles have one correct solution and everything else is wrong and doesn't work, while with a problem you're given some tools and an obstacle and just let loose. It's so much more satisfying to find your own solution that it is to reach the end and realize you were being sneakily handheld through it to make sure you found the only possible way through. I've done a few good problems where I reach the end, then immediately reload the save from before and try some different routes just to see if it works.

Puzzles do have their place though, especially in tutorials.

Escort Missions. Especially when pathfinding AI was terrible.

Quick Time Events in a game that it isn't the focus. Halo 4 had exactly two quick time events. One in the first level and one in the last level.

Crafting. And jumping games.

Probably the Enemy Boxer from Lego Indiana Jones: The Original Adventures. Canonically he is a mechanic but they don’t even give him the wrench ability which isn’t even that special of an ability, and then he dies like a wimp with his plastic still-alive head getting chopped off by the plane that he’s supposed to be repairing. An idiot who would punch an anvil three times in a row deserves that sort of graceless demise.