The purpose of Agario is simple. As soon as you select a name and a server, you will spawn as a tiny colored blob. You will drift around and encounter small pellets, which you should eat to grow. When you grow large enough, you can also absorb other players as well, but only if you are bigger than them. You will see that as you absorb more and more blobs, your own blob gets larger and larger. While you are looking to absorb smaller blobs, however, larger blobs will also look to absorb you. The objective of Agario is to try to avoid getting eaten and to grow as big as you can. The game’s simplistic, yet tactical, play-style lures people in, causing them to spend hours and hours playing.
There are currently eight servers in the game (US West, US East, South America, Europe, Russia, East Asia, China, and Oceania). You don’t have to live in the server region to play on that server. So if you live on the Eastern coast of the US, you can play on the Oceania server, for example. However, it’s best to stick with a server near you in order to decrease potential lag while playing the game.
There is also an option to use skins in the game. Agario skins allow you to play with a specific image depending on which skin you use.