World of War is mostly played in multiplayer, although you will be able to create and send custom missions and campaigns to the public and/or your friends, and there are some pre-made missions and campaigns available for free download.
Players will be able to make their own levels, play them and send them to whoever they want. Unlike most other shooters, there is no default Campaign mode.
The main game is played as multiplayer, as is the world, and the main war. Players can meet other players here, and several different types of servers are here.
This game has the idea of having multiple games sharing servers, and may be the first to do so.