As for Half Life 2, I still love it. It's a lot better than most modern FPS types of games (last few years have been very bad) as it has a sense of distance, alienation in these huge landscapes, an example is that you can see off a kilometre when riding down the coast and elements you have to work with to progress change in that landscape. It's very relaxing if you just want to ride on down the coast and stop off now and again. You will meet some baddies but you can dispose of them and return to the tranquility.
Logged off last night having just reached the dreaded chapter where it briefly turns into a horror film:
You can try Geforce Now for free btw, can play for an hour at a time.