Agar.io is a massively multiplayer action game developed by Matheus Valadares. Players control a cell in a map representing a petri dish; the goal is to gain as much mass as possible by swallowing smaller cells without being swallowed by bigger ones. The name Agar.io comes from the substance agar, used to culture bacteria. Source: Wikipedia, "[en.wikipedia.org/wiki/Agar.io Agar.io]", available under the CC-BY-SA License.