It's fun for the first little bit, until you notice the bright colors and the "COPPA Compliant" logo. From a technical perspective, having a game that allows people to write custom scripts to do everything but has nothing built in is a lagfest for weapons and vehicles. If I want to kill stuff, I'll play CSS or Doom. It's novel and fun if you want to try your hand at game design, but it gets stupid fast.
haven't had any trouble with lag.... maybe cause I live in NZ and everyone plays at different times to I do. I can't bebothered designing anything new (Apart from battle fields) in the way of weapons and vehicles and let others do it. I just play it for the destruction of minifig wannabes and lego constructions that people have painstakingly placed together to form lego buildings. It is pretty basic, but there's nothing wrong with that.