Paper IO unblocked is one of the most popular multiplayer games. It is a simple game with simple rules. You have a square object and you need to close the transparent lane with your territory. Your goal is to control the entire board and eliminate your opponents. The game is very addictive and can be played in teams of two or more. It is available on many websites and is free to play. There are a variety of different versions of Paper IO, including the online version.