Slither io

 Slither.io (stylized as slither.io) is a multiplayer online video game available for iOS, Android, and web browsers, developed by Steve Howse. Players control an avatar resembling a snake, which consumes multi-colored pellets, both from other players and ones that naturally spawn on the map in the game, to grow in size. The objective of the game is to grow the longest snake in the server. Slither.io is similar in concept to the popular 2015 web game Agar.io and is reminiscent of the classic arcade game Snake.

The game grew in popularity following its promotion among several prominent YouTubers such as PewDiePie, and topped the App Store soon after its release. Slither.io's browser version was ranked by Alexa as one of the 1,000 most visited sites in July 2016, while the iOS version ranked first in the most downloaded apps on the App Store. A mobile version of the game for Android was released on March 27, 2016. The reception of the game was positive, with reviewers praising its appearance and customization but criticizing it for its low replay value and the high price users were required to pay to remove advertisements (although as of 2024, most versions of the game no longer show them).

The objective of the game is to control a snake, also known as "slithers", around a wide area and eat pellets, defeating and consuming other players to gain mass to grow the largest and longest in the game. Once players are spawned into the virtual world, their avatar remains in constant motion. If the player's snake's head collides with another slither's body, the player will die. The defeated avatar's body turns into bright, larger shining pellets for other players to consume. These pellets that remain from "death" of an avatar will correspond to the color of the avatar itself, and are both brighter and bigger than "normal" pellets, which spawn naturally throughout the world. Normal pellets do not give as much mass as pellets dropped from other snakes. "Chase" pellets will appear individually in various places of the world; when eaten, they give a greater amount of mass than pellets dropped by other snakes. Chase pellets avoid snakes and flee when they draw near. Chase pellets can be obtained by boosting.

By pressing and holding the space bar, up arrow, or left/right mouse button, or double tapping the touch screen on mobile, the player can use their boost, which causes the avatar to speed up using mass. When the button is released, or the finger on the touchscreen on mobile, the snake will stop using its boost. As a player uses their boost, the snake loses mass, causing the snake's size to shrink slightly as the player continues to boost. The mass that is lost from the boost appears as a line of small pellets where the boost was used. The mass lost can be regained by consuming the pellets. Similar to pellets dropped from defeated avatars, the boost pellets correspond to the color of the avatar. The boost feature is useful to outmaneuver and defeat opponents. A common strategy that is used by players to defeat opponents is by coiling the player's slither around a smaller opponent's in a loop, until the opponent, trapped in the tightening loop, crashes into the player.

There is a border that confines avatars within the circular game board. If a snake hits the border, the player automatically dies without turning into pellets. On each server, leaderboards are displayed at the top right, showing the top ten players with snakes that have the most mass out of all the other slithers in the entire server.

There are 16 default skins, each one a different solid color along with multiple repeating patterns. The colors are randomly chosen when the player joins the server. Players can choose to customize their snake's appearances using custom skins with unique designs including different countries' flags, as well as skins with motifs and colors representing well-known YouTubers, such as Jacksepticeye, Jelly, and PewDiePie. The player may also choose to create their own skin, with a tool known as "Build a Slither", which shows the different colors that an avatar can be made of, that can be placed on the worm upon clicking. Previously, in order to unlock custom skins in browser mode, players were forced to share the game on Twitter or Facebook using the external links found on the website. By June 2016, the ability to add skins was also added to the iOS and Android versions.

According to game creator Steven Howse, he was inspired to create the game while he was experiencing financial problems. As a result of these financial issues, he had to move from Minneapolis to Michigan, where he realized the popularity of 'Agar.io'. He had long wanted to create an online multiplayer game, but Adobe Flash was the only development option at the time, but not wanting to use this method, he paused the idea for a while. Howse finally created the game when he realized that WebSocket, a low-latency protocol supported by most major browsers, was sufficient and stable enough to run an HTML game similar to other games such as Agar.io. The most difficult part of the development was in making each server stable enough to handle 600 players at a time. Howse struggled to find space on servers with enough space in regions where there was more demand and tried to avoid cloud services like Amazon Web Services, owing to the high cost that these services would incur based on the amount of bandwidth used.

After six months of development, Slither.io was released for browsers and iOS on March 25, 2016, with servers supporting up to 500 players. Two days after the iOS/browser versions' release, an Android version was made available by Lowtech Studios. The only way Howse could make revenue was to display advertising in the app after the player's worm died; this option could be removed for US$3.99. He chose not to sell virtual currency or power-ups so that those who paid would not have an advantage over players who did not. As there was no money to advertise for the game, the only way to promote the game was the various let's plays by players on YouTube, including PewDiePie, who had more than 47 million subscribers at the time. The success of the game would cause Raw Thrills to develop an arcade version a few years later.

In the weeks following the release, Howse worked on updates to stabilize the game and provide a better experience for players. In addition, he plans to add new features, such as a "friendly mode" that allows people to set up teams, and a way for the player to choose a server to play on. Howse said that two major gaming companies had approached him to buy Slither.io. He had considered the idea, since he felt that it was stressful to maintain the game.