Top Defense    You are the Commander of the space battle station. Below you, on the planet's surface, your enemy is trying to your capture deadly missile silos. Be a hero and DO NOT allow your enemy to seize those silos. Help should arrive soon... hopefully. Your station has a rich weapon system. Cannons, minefields, homing missiles, etc, but right now, most of them are damaged... Mouse - Aim, Left Click - Shoot (Hold down to continuous fire), Drag mouse to fire "Vulcan" or "Barman", 1-8 Keys - Switch weapons, Space Bar - Upgrades (reset to zero after every mission)