You will receive 10 points for every missile you intercept and 50 points for every city still alive at the end of each round. Each silo can only hold 15 missiles per round. At the end of each level the silos will be reloaded and repaired and one city will be rebuilt.
"Instead of shooting where I was, you should have shot where I was going to be. Muahahahaha!" - Lrrr (Futurama)