Some users recall a variant called or "Google Goo" where the logo drips down the page. While not a canonical Mr. Doob creation, several copycat experiments on CodePen and Glitch have blurred the lines. If you search YouTube for "Google Slime Gravity," you'll find videos of hacked versions where the letters of Google stretch and deform like a viscous fluid.
While "Google Gravity" is his most famous search-themed work, Mr.doob has created several other liquid and physics-based web experiments: google gravity slime mr doob link