Mastan

I found that this game is still available officially, no need to use Internet Archive(yet): http://www.bbc.co.uk/sn/prehistoric_life/games/dinosaur_world/ (click "Open" under the picture to open actual download page) I have no problem with the sky running it on laptop with Win10 and Intel videocard. Game uses old DirectX version, sometimes dgVoodoo 2 helps with some problems of old APIs on modern systems.

"SteamVR headsets" also supports WMR through Windows Mixed Reality for SteamVR. I don't know if it's true for all games, but I've seen games that are not marked with WMR support, but still work. E.g. Batman: Arkham VR. Controllers in-game have non-native look, but that's minor. Some games(e.g. Obduction before official WMR support patch) use not very comfortable tracked controller bindings, but otherwise work. WMR also supports OpenVR, I played one standalone game by choosing OpenVR in settings. So, in my(not very big) experience it's more about APIs than headsets.

Moscow and its suburbs: 3 internet providers I have assess to all block it. https://community.pcgamingwiki.com works though, it uses another IP.

You can use "FireX Proxy" firefox addon or similar ones. PCGW just recently changed its IP to 159.203.146.174 which has been already blocked since April 2018. It's about Telegram blocking, so I don't think this ban can be easily lifted. Unless PCGW introduces additional IPs from other ranges.

For Steam demo links, Steam always opens main game store page instead of some "demo page"(which does not exist). Like this link will lead to https://store.steampowered.com/app/779290 Maybe URLs for Steam demos should be like this, direct downloads? steam://install/780490 Not sure if "steam" web prefix is supported by wiki tho.

June 6 have been changed to June 8 in the end. That user should've used "show preview" button instead of posting multiple fixes of his errors.

GIF shows that better. Open picture in full size for better distinction.