Agar.io is a science-based, battle-arena game that features common play elements found in snake, worm and similar slither-style games. The player's primary goal is to grow a cell as large as possible on a grid background that functions as a laboratory Petri dish by helping it eat agar pellets and other players' cells.
The player's cell starts small. If they want it to survive, they must move it through the agar pellets quickly until it has grown large enough to consume other cells. They can also split it into more than one cell to increase its mass and hunt smaller cells faster. When near a smaller cell, they merely need to time the split to shoot the secondary cell at an opponent.
As the cells grow, their movement slows down, which makes it more difficult for the player to move them away from threats. That said, the player can direct a cell under a larger green cell with spiked borders that represents a virus to briefly hide from other players. Although a virus causes damage and reduces cell size, it also serves as a temporary relief from battle.
Agar.io offers five gameplay modes (FFA, Battle Royal, Teams, Experimental and Party Mode). If the player has an account, they can perform upgrades and receive access to daily quests and gifts.
