Agar.io is a very good game to play when you are bored.Like Slither.io, Agar.io is a game in which you need to grow up by eating points or other players.
To be the best player on the leaderboard ,or even to be a champion in Europe is a pretty tough quest.
The biggest players are very annoying because, even though they are slow, they can distribute in smaller sattelites that can catch you if you are near them.
Anyways, this is a very good game that will not let you leave it.