Remember old Nokia's Snake? Slither.io is pretty much a multiplayer version of it. You play against other players online. If you are bigger than them, you can eat them and gain their length.
Careful not to bump other snakes, or you'll die and your body will become bright and nutritious pieces of light for others to feed on.
Everybody has a chance in slither.io: even though very small, you can still intercept a large player and almost instantly become the biggest one alive.
Try now one of the most addicting games ever!