Years ago, Agar.io has been created and era of iO games was started then. Play Agar.io unblocked game for free online as the beginning of online iO games. Set a nickname to play Agario unblocked as a guest, or you may prefer to login with your social account such as Google or Facebook. Gather colorful circles for increasing your score and growing up your avatar. Growing up will help you to beat opponents smaller than you. Scroll mouse for moving on game arena for your main purpose.