Slither.io really doesn’t need to be reviewed. You can play it right now on your phone or browser and it’s simple enough to get the gist of it within a minute or two of playing. But you know what? I’m going to review it anyway. It’ll make for good writing practice. So please humour me as I write the most pointless review ever.
Slither.io is a multiplayer game for browsers and mobile. You control a snake. The flat circular map where the game takes place is covered in points. When you eat these points, you grow in size. The goal is to eat as many points as you can and grow as long as possible.
Slithering in your way are hundreds of other player-controlled snakes, each with the same goal: eat as many points as they can and grow as long as possible. There is no winning this competition; the game goes on and on and on until you all inevitably crash and die. When snakes die, they drop all the points they collected for everyone else to gobble up. Slither.io is an endless game of slithering and scavenging, ensnaring and evasion. No matter how big you grow, no matter how slippery you are, all sneks must die.
What makes Slither.io hard is that snakes can’t stop moving forward. They keep moving until they crash into the edge of the map or the body of another snake. To avoid crashing involves constant situational awareness. Areas can sometimes get so crowded that there is very little room for manoeuvre, and even in places with lots of space other players can easily cut you off if you’re not careful. The overhead point of view only goes so high, giving you only a second or two to respond to developing threats.
It’s easy to survive a long time if you’re extremely careful, but an aversion to risk usually results in slow growth. If you want to grow quickly, you’ll have to be daring. You’ll have to spend time in crowded areas and dive for the points dropped by fallen snakes before other players can gobble them up. You’ll also have to learn how to cut off and trap other snakes while avoiding being cut off and trapped yourself.
Excessive care can also be dangerous. Snakes can pass over the length of their own bodies, enabling them to protect their heads. This is a useful tactic, but it must be used wisely. Snakes’ tails naturally contract over time, meaning that unless a player makes a constant effort to expand beyond where their body lies, they will gradually occupy less and less space. Occupying a small amount of space is dangerous because it makes it easier for other snakes, even ones that are smaller than you, to surround you. Once surrounded, it’s very rare you’ll get an opportunity to escape; the surrounding snake will either have to present their head to you or be scared off by a surround attempt by another snake. Or perhaps they’ll decide you’re too small to be worth it; that happens too sometimes.
In some ways, the game becomes easier the bigger you grow: your viewpoint soars higher, you can more easily hover up points with your big head, and you have more length to protect yourself with and cut off and surround other snakes. Only in one way does the game become harder: bigger snakes have bigger turning arcs. This makes big snakes especially prone to crashing into other snakes when they’re not careful. It can be a terrible feeling to grow to a huge size, dwarfing all the snakes around you, only to make a stupid mistake and be forced to watch helplessly as you slither towards a collision you cannot possibly turn away from. As a big snake you may find it easier to grow, but you will also find that your mistakes are more harshly punished.
Despite having more to lose, though, big snakes are incentivised to maintain an aggressive playstyle – deliberately cutting off and surrounding other snakes – because the bigger a snake gets the less value each individual point has in proportion to the points they’ve already gained. In other words, a small snake can grow a lot from the points dropped by another small snake, but the growth a big snake will get from the same deposit of points will be harder to notice. Big snakes must therefore consume other big snakes, or lots of small snakes, to grow at a consistent and noticeable rate. This entails acting aggressively. As a result, there is always a strong incentive to play dangerously – even if you’re a big snake with lots to lose.
Slither.io is a game you can’t win. It’s a game about surviving as long as you can and growing as large as you can. Because surviving requires constant attentiveness and split-second decision-making, it can be stressful if played too much. The tension of evading obstacles, causing other snakes to crash, growing as big as you can, and surviving as long as you can is an engaging yet simple gameplay loop better enjoyed in small bursts.