In 1986, the world's worst nuclear disaster occurred at the Chernobyl Nuclear Power Plant. Soviet authorities established an 'Exclusion Zone' around, but a second explosion hit the reactor in 2006, creating The Zone as we know it – dangerous place, filled with mutated creatures, deadly radiation, and a strange, anomalous energy. The Zone was cordoned off by the military, who would shoot on sight anyone foolish enough to get inside.
Year 2012. The Zone is still a dangerous place and a threat to all mankind. Mercenaries, bounty hunters and explorers ventured further and further into the heart of the Zone driven by reports of strange 'artifacts' imbued with anomalous energy. To sell them on the black market or trying to find the 'truth' behind the Zone. Whatever their motivation, over time these individuals - Scavengers, Trespassers, Adventurers, Loners, Killers, Explorers and Robbers - have become known as S.T.A.L.K.E.R.s.
https://store.steampowered.com/app/4500 ... Chernobyl/

Quite honestly one of the most atmospheric FPS games out there. Excellent sound design and ambience makes every moment in the game incredibly sense and relatively realistic combat mechanics and fantastic makes every shootout even more intense. It gets billed as a Survival Horror although barring a handfull of locations (The Lab areas being the most notable for being spooky) the games more tense and atmospheric rather than actually scary.
The game does have a fair bit of that slavic jank to it, but that makes it all the more charming tbh. Plus there's plenty of fan made mods and fixes out there if you dont want that jank.
Just a tip: AFAIK the difficulties have this weird thing there they also nerf your damage as well as the enemies. Making most weapons useless on lower difficulties. Best to play on medium or higher.
Anyway here's some of the soundtrack to give you an idea of it's atmosphere.
Ambience:
Main Menu Theme:
Finally The Meme Track/Bandit Radio: