Build Royale (.io), a multiplayer.io gaming game, is where battle royale is the main theme. In a massive gunfight, you will face off against other players. Your only goal is to win. The pickaxe is only what you will need to mine materials. These can be used to build protective walls.Build Royale (.io), a multiplayer.io gaming game, is where battle royale is the main theme. In a massive gunfight, you will face off against other players. Your only goal is to win. The pickaxe is only what you will need to mine materials. These can be used to build protective walls.