From 2015 to 2021, Google featured a special Easter egg to commemorate Super Mario Bros.' 30th anniversary. Released on September 13, 1985, in Japan, this game includes the iconic Mario coin clinks and a charming surprise after every 50 clicks.
Though this Easter egg isn't readily found in Google search nowadays, you can relive the nostalgia with a fully functional version on elgoog.im. Take a break and play this timeless classic today!
Update: As of 2023, it appears this Easter egg is more visible, popping up when you search for "Mario" or "Super Mario" on Google.