Agar.io is a massively multiplayer online action game.
The objective of Agar.io is to grow a cell on a petri dish by swallowing both randomly generated pellets (agar), which slightly increases a cell's mass, and smaller cells, without being swallowed by larger cells. The browser version currently holds four game modes: FFA (Free-For-All), Teams, Experimental and Party. The mobile version of the game includes FFA (Free-For-All) and Rush Mode. The goal of the game is to obtain the largest cell; players must restart when all their cells are eaten. Players can change their cell's appearance with predefined words, phrases, symbols or skins. The more mass a cell has, the slower it will move. Cells gradually lose a small amount of mass over time.
Viruses are green, (red in Rush mode in the iOS mobile version) spiky circles that split large cells. Viruses are normally randomly generated, but can also be generated when receiving enough mass, to the point of splitting into two, hence creating a new virus.
Players can split their cell into two, and one of the two evenly divided cells will be flung in the direction of the cursor. This can be used as a ranged attack to shoot a cell in order to swallow other smaller cells, to escape an attack from another cell, or to move more quickly around the map. Split cells eventually merge back into one cell. Aside from feeding viruses, players can release a small fraction of their mass to feed other cells, an action commonly recognized as an intention to team with another player. However, a small portion of the ejected mass is lost. Players can also spawn from ejected mass. A player can also eject mass to trick enemies into coming closer to the player.
This article uses material from the Wikipedia article Agar.io, https://en.wikipedia.org/wiki/Agar.io, which is released under the Creative Commons Attribution-Share-Alike License 3.0, https://creativecommons.org/licenses/by-sa/3.0/.