In Agar io, you start as a small cell and navigate a large map filled with other players and randomly generated pellets called "agar." The primary objective is to grow as large as possible by eating these pellets and smaller cells. However, the larger you become, the slower you move, making you a target for other players.

The agario game features several modes, including Free-For-All (FFA), Teams, Experimental, and Party modes on the browser version, and Classic, Rush Mode, Burst, and Battle Royale on the mobile. Each mode offers a unique twist on the core gameplay, keeping the experience fresh and engaging.