While there are many IO multiplayer games based on worms, Slither.io was one of the first. While other multiplayer games have tried to reinvent the formula, Slither.io, also known as Slitherio, remains one of the best in the genre due to its tight controls and great graphics.

Playing Slither.io is easy, as all you need is a mouse. Your worm is continually in motion and will move in the direction of your mouse pointer. Your objective is to eat the glowing orbs found on the screen while trying to avoid crashing into another player-controlled worm. The more glowing balls you eat, the larger your worm grow. You have one defensive move in your disposal: a quick dash. You can pull off this boost by clicking either mouse button. However, this dash attack will use up some of your stored energy which will cause your worm to shrink. 
Slitherio is a game about risk versus reward. While you gain a small amount of size for each glowing orb you eat off the ground, eating orbs dropped from defeating another player will give you a massive size and score boost. However, while you are trying to trick another player into smashing into your worm, that player is also doing the same to you. It only takes one wrong miscalculation to end up as a feast for another player's worm. As you get larger, it becomes easier to trap smaller worms within your large frame; however, your worm turns more slowly, allowing a little worm to speed in front of you at the last second. Giant worms are also targets for all players due to the large number of globes they drop upon death. Only players who take risks will obtain the highest score.

You'll always need to stay on your toes as Slither.io has a huge player base. While other IO multiplayer games  like Agar.io have flashier graphics or more gameplay features, Slither.io maintains one of the largest player bases. You can't go more than two seconds without spotting another player, which means the action in Slither.io always remains intense. With its cartoonish graphics and lack of sound or music, this is the perfect game to play at school or work. If you want to stand out from the crowd, you can share the game on Facebook or Twitter to unlock extra skins.

Slither.io is the sort of game where you'll find yourself queueing up for just one more game even though you should have been in bed an hour ago. With games averaging five minutes or less, Slither.io is the perfect game to unwind from a long day.