Since Agar.io's release on April 28th, 2015, .io games have gained popularity through accessibility and exposure through Let's Play videos. Notable YouTubers, including Markiplier and Jacksepticeye, have made series revolving around these games. Within the past 4 years, .io has expanded out of Agar.io into countless other games. Some are zombie-themed, others have war robots. Some lag like crazy, others run smoothly and extend their reach to mobile devices.