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.
Ah, I missed that comment. They even build an entire physics engine for this website, to resemble the physics in Half-Life 2. Objects like text and images interact with each other and stack on top. Love it!