In Heli Intrusion you must survive waves of invading helicopters. Shoot them with your cannon and try to rotate them until they explode. Make them knock into each other to create cool chain reactions. For each exploding heli you earn money to upgrade your cannon with better ammunition or to upgrade and repair your health. Shoot the funny ragdoll style soldiers to make more money. Target with mouse. Click (and hold mouse button) to shoot. Try to hit the helicopters at front or back to make them rotate faster. Try to let them knock into each other.