Having trouble shooting down all those Jocks before they crash the gates of the Observatory ?? Well here's what to do...You have to stop them....
Before the mission, go buy the maximum amount of marbles...Then, during the mission, after they break through the barricades, and you are running back to the Observatory, STOP and spread all the marbles on the paved portion BETWEEN the 2 stone pillars that the Jocks will come through...Then run up and man the spud gun...They will all slip and fall, making them real EASY targets.....