Alright here it is: There are 2 parts of the city, The Social/Creation lab and the action district, in the social/creation lab you don't lose gametime and you can talk, and create DUH
In the action district you shoot and die, you use gametime here... with enough "Realtime Worlds Points" (RWP) you can buy gametime, you get that through payment, or from making money through your creations in the game You can essentially play the game free if you create ALOT and are very famous within the game.
You can buy: 20 hours of gametime in the action district (Still infinite amounts in the social) or 30 days playing or not, even in the social district this gets used, at school -- yupp Just like WoW, only there will be no recurring fee... Make sense, ask me for more clarification