Agar.io

Agar.io is a Massively-multiplayer top-down strategy browser game. In Agar.io, the player manipulates a circular cell using the mouse and keyboard buttons. The goal of the game is to enlarge the cell by swallowing non-player cells which are randomly scattered around the map. Other players that have smaller cells than the player are also able to be swallowed. Originally a browser game, Agar.io entered Steam Greenlight and was subsequently “Greenlit” by the community, with the developers indicating that they planned to add more features not available in the web version of the game.
Agar.io has quickly become popular worldwide. Before the Turkish 2015 elections, Agar.io has been used in Turkey for political reasons; some political parties have also used Agar.io in campaign posters as a symbol of support.
Players can also use skins.