slither.io is an online game where each player has to control a huge worm trying to eat all the colored balls that across your path. Eating as many balls as possible won't be an easy task, though because you'll be up against other worms competing to eat as many colored balls they can.
The gameplay and concept for slither.io is very similar to Agar.io and other titles from the same genre, but there is one fundamental difference. In slither.io you'll always get the chance to defeat any enemy, regardless of their size or yours. All you have to do is get the other worm to butt heads with your worm's body.
When a worm is defeated, the rest of the worms will get to eat it to become bigger. That's why a good strategy is trying to follow other bigger worms while waiting for someone else to defeat them, so that you can eat it and get bigger. Just like a vulture!
slither.io is a game that's got a very fun concept, with some technical issues. The game is basically silent though, as it doesn't have a soundtrack. And system controls aren't nearly as good as they could be.