Rainbow Six Siege made me much better at FPS games.

Unironically old school runescape. Playing it for years ingrained the concept of efficiency into me. Now I'm able to do well in games where mechanically I'm still shit because I'm constantly trying to use my time as efficiently as possible.

Life

Counter Strike got me through hard times in school an taught me how to communicate efficiently. It also got me over that cringy "i rage in video games" phase that many people are still in.

Elden ring taught me that I had to be calm when playing games. It taught me to know that I will be able to clear content, its just a matter of when. I used to think of games in terms of, can I clear this content? Now I think of games in terms of, how long will it take me to clear this content? I also realized that single player games aren't hard. They are literally designed to be beaten.

I also learned that I play a lot better when I'm more focused on my body than the screen. I started bringing the same mindsets I use for sports into playing games and it helped a lot. It used to be that when I played games the screen was all that existed. Now I focus more on the pleasure of my fingers gliding across the keyboard, or just the contentment of experiencing my body doing something it enjoys.

Margit the fell omen and Godric the grafted took me like 30+ tries each. I beat blood flower lady on the second try (with mimic tear) and the final boss in maybe 6 tries (with a less powerful tear). I was beating bosses on the first or second try pretty consistently, like the starbeast things, ancestor spirit, dragonkin soldier, magma wyrm, and some of the crypt dungeon bosses.

I had put 40 hours into hades back in 2020 or 2021 and I probably cleared the game with no heat 5 or so times in those hours. More recently I sunk my teeth into hades and put in another 60 hours. In those 60 hours I got 100% on steam and was able to clear the game on +17. I also got through the first phase of hades on +32. But, I realized getting good enough at that fight to get through all 3 phases would've been rough. But regardless the difference in skill level was really apparent to me. It was so much fun to actually get constant story progress because I was actually clearing the game.

Well, I can tell you this. I grew up playing Mega Man. People say those games are hard, but I have them all memorized, so they're all pretty easy for me.

Sometimes I play platformers that people consider hard, and I'm just disappointed by how mind-numbingly easy they are. Celeste is one example. I kept thinking, surely it must get harder. Maybe when I do the B sides. Surely there must be at least one part I struggle on. There never was. I never found anything hard about the game. The story was amazing, though.

So anyway, my answer is Mega Man. Not Mega Man X. Those games are amazing - quite possibly my favorite platformers of all time - but they're too easy to fit into this category. The classic, 8-bit mega Man games from the NES (Mega Man 2 excluded. That one is also too easy).

Mass Effect made me far better at multitasking and not letting myself get tunnel vision on an objective.

Sure I'd played Gears of War, or RTS's that used the traditional rock, paper, scissors method of unit dominance, and resource management.

I'd just never played a third person shooter that expected me to combine all of those skills into a single gameplay loop which required constant shifting from power/defense based problem solving to accurate shot placement and squad positioning on the fly.

Mirror's Edge. I would try over and over to improve times on the time trials, and I found that I did better when I took a break and relaxed for a few minutes, or overnight, before trying again. It has improved my playing other games as well as my real life efforts

Planescape: Torment made me slow down and realize a game can be an entire world onto itself and I shouldn't skim over stuff I read.

The Outer Wilds is probably the most recent game that changed how I approach stuff. It's so good. Nothing is given to you, you have to figure out everything on your own. It's good for developing patience and curiosity.

For twitchy gameplay type stuff, I recommend Radiant Silvergun. Makes every other shmup feel like they're in slow motion. That game is why I was able to beat any of the Touhou games.

StarCraft II made transitioning to League of Legends easy. I also played a lot of Kovaaks which made my aim generally better in FPS games and it helps with osu! too.

Celeste, Guacamelee, and Monster Boy in the Cursed Kingdom all made me better at platforming games.

The last of us multiplayer made me a better sniper. Smash bros amplified my reaction time. And halo improved my hand eye coordination with grenades.

Bayonetta, and Burnout 3. I got really good reflexes and timing.

And way way back when I was super absorbed playing Manhunt I got uncannily good at spotting dark shadows at night to hide in.

It's not really in the spirit of the prompt, but learning the NMG speedrun of LttP has really improved my movement efficiency in games simply because I'm always thinking about it now

Nioh 2

Dead by Daylight. Spending so much time chasing or being chased by other players has definitely improved my tracking/flanking abilities in other games, as well as pathing and following players audibly. I may not be a great shot, but I know exactly where you’re going and how to cut you off.

Also utilizing mindgame strategies can really fuck with people in other games.

Edit: Also also, I don’t get tilted nearly as easily as I used to. DBD sucked all the rage out of me.

Edit 2: My first point also applies defensively, in that I know how to more effectively lose someone if necessary.

I feel most improvement playing turn-based games, like TFT, Hearthstone, Slay the Spire.

spider solitaire for the windows 98

it thought me a lot about how to move the mouse around the screen and also built up my tolerance for horror games by introducing spiders into the solitaire universe

DayZ SA hardcore, my reactions have improved and I have become more cautious as a player, especially of people.

Counter strike makes any single player shooter trivial. The best they can do for difficulty is make headshots not actually kill the target in 2 or 3 shots.

Platformers are easy after super meat boy.

The original Deus Ex will train you to explore and scrounge for every bit of ammo. Making your skills from counter-strike even more valuable.

Apex Legends really honed my skills with shooters on keyboard and mouse. I always thought I was terrible at shooters. Turns out it was just the controller I was bad with. I always played with friends and it greatly helped our tactical communication and snap decision making skills too. We found out who the natural shot callers were and who can't be trusted to make the calls in a tense situation, lol

The speed and random nature of Spelunky really helps build gaming skills.