https://www.half-life.com/en/halflife2/20th
Go down to the page and click the gun. Then you can pick up every element on the page, such as graphics and text. Put it in the bin or throw it around; the window wraps on left and right side (like if it is a Portal…). I find this really cool.
You are right. I just tested it on my mobile browser and it just says “Perhaps on a desktop browser?”.
But I found a way to make it kind of work, but its not as good or seemless like on a real desktop PC. It halfway works if you switch your browser mode to Desktop mode. In your browser menu (the 3 dots, what’s called? hamburger menu?) should have an option to enable “Desktop site”. Then reload page and if you click the gun, it should pop out. Now try to click an element on the webpage, maybe the text. If it does not fall, click again. Unfortunately you can’t (or I can’t) hold an element and drag it around.
It’s really a shame.