Slightly annoyed as I bought Half Life a couple of weeks ago. Even more annoyed, as it turned out that it doesn't run on Windows 10 - it installs and launches, but isn't capable of any sort of useful FPS. I ended up installing Windows XP in a virtual machine and then installing HL on that - I get native resolution and fps that matches my monitor.

Steam does have history selling games that can't be played. I bought Max Payne a few years ago at only to find that doesn't run on Windows 10 either (iirc I used WINE that time).