For me its Subnautica because the progression works so well. I've tried lots of survival games and sandbox games with similar progression afterwards, but none of them had the same impact on me. It's also because of the genre - Sci-fi on an alien planet, discovering what actually happened, and all that baked into some real satisfying gaming loop. Also, without spoilers, the end sequence always makes me emotional, regardless of how many times I've played it. It just speaks to me on a personal level.
You might misunderstand how their "ratings" work - they simply collect all reports and when people had trouble with the game before, and gave a negative or "tinkering required" rating, it will show in the overall stats.
Depends on what you are playing, but gaming in Linux has come a long way. Some games won't work due to companies not enabling their (rootkit) "anti-cheats" for Linux, but other than that, there's more and more games that simply work by the day. Check out https://www.protondb.com/ to get an idea of what's working at the moment.
