The other thing is when it comes over the intercom: Forget about Freeman! Anyone still down there is on there own!

The worldbuilding in Half-life was so good. You weren't a character walking into rooms and enemies would attack you, like Doom and Quake. There was a big event happening, and you were just a part of it.

It's quite memorable in VR as well! If you get the chance I highly recommend playing HL Alyx with a valve index setup.

It was on par with my first playthrough of the original HL so many years ago.