The 2006-engine version of Half-Life 2: Episode 1 runs on Windows 10/11 with no configuration [1], outside of getting Steam to download it. I recall installing The Elder Scrolls IV: Oblivion on a Windows 11 machine, which just needed Directx 9c to run.

[1] https://steamcommunity.com/sharedfiles/filedetails/?id=28643...