- F1 2024 didn't load due to anti-cheat
- Dragon's Dogma 2 and Resident Evil 4 had non-functional raytracing
- Cyberpunk 2077 with raytracing on consistently crashes when reloading a save game
- Dying Light 2 occasionally freezes for a whole minute
- Starfield takes 25 minutes to compile shaders on first run, and framerates for Nvidia are halved compared to Windows
- Black Myth: Wukong judders badly on Nvidia cards
- Baldur's Gate 3 Linux build is a slideshow on Nvidia cards, and the Windows build fails for some AMD cards
If you research these games in discussion forums, you can find some configuration tweaks which might fix the issues. ProtonDB's rating is not a perfect indicator (BM:W is rated "platinum").
And while Steve says measurements from Linux and Windows are not directly comparable, I did so anyway and saw that Linux suffers a 10-30% drop in average FPS across the board when compared to Windows, depending on the game and video card.