This is the game that convinced me the “Verified” title is completely meaningless. Left 4 Dead 2 is a terrible experience on steam deck. For one, it just does not run well at all. In single player at least, there are frequent stutters and sustained frame rate drops under 50 when the action picks up…
What?? Why does this game of all games not LOCK to 60fps? I mean it should benefit from being old af, bespoke valve optimizations, and source engine generally running well.
Another thing is the controls are so bad. The joystick feels super weird and unnatural with the steam deck controls and an external xbox controller. Super bizarre.
L4D2 is the most egregious example of this but honestly I put zero stock in the deck rating system anymore. I have had flawless experiences with games that are playable or unsupported, and I’ve had Verified games that would not even START! (Limbo comes to mind, its verified but would not start under the default linux runtime, I had to use proton to get it running)
Ran fine for me when I played it. Was especially great with gyro. Maybe check your settings?