The game is Black Mesa, it is a high quality remake of Half life 1:
VR Mod is a bit tricky to install, but it pays off later
Here is an “older” link for youtube guide how to install mod. Now is easier, as “Mod Organizer 2” is included together with mod. If you use standard steam games directory (C:/…steam/common…) then it will be really easy for you. I had to change my location in several files to my D: disk…
First you need installed Black Mesa, Half Life 2 Episode 1VR + Episode 2VR. Yes, you need to own them all, and all on Steam!
Then you need Mod - the link is in youtube video description.
I highly recommend this mod, /game, it is really beautiful.
Here, as a bonus, 1 more video about making of Black Mesa:
PS: VR mod actually use HL2 Episode 2VR mod in background, which is excellent. 6DOF, shoot weapons with 2 hands, crowbar swing, weapons reloading and ladders climbing as IRL…