Slither.io is a traversal action game where you control a snake that needs to eat coloured pellets to grow in size. You play by directing your snake to both collect the pellets but also to get opponents to run into you - as they then die and you can steal their pellets. It stands out for being really popular because you can easily play it in a browser or smartphone.

It's a game that has periods of viral popularity. Although it's now less popular it's still a really enjoyable game. Although play starts as a simple task of avoiding other snakes and collecting pellets, you soon need to develop tactics to trap and trick other players. You might quickly guide your snake in front of another player. Or you may encircle another large snake and then slowly constrict your path until they have no space left.

The result is a simple game that requires a surprising amount of skill and perseverance to do well at. There are a large number of similar games on this theme:

• Agar.io: Control cells trying to absorb each other.
• Paper.io: Control a square of paper trying to turn the playfield into your colour.
• Diep.io: Control a tank to outgun other players.