MG Towers and MG Nests: armed with only Machine Guns but a CO claims that MG Towers have a blind spot beneath them.
RPG Towers: work against tanks but beware of Battlestation Super Tanks and Bazooka Vets.
AA Towers: cause trouble for aircraft, especially gunships.
Sea Forts: cause problems at sea with AA guns and RPG Towers but Battleships are perfect for these enemy forts.
Forcefield Generators: block movement for only ground units. Aircraft can fly over them.
Sandbags: cover points for infantry and defense against small arms fire. Mortar, Tanks, artillery and aircraft are perfect against them.
Naval Guns: guns used for defense against ships. They are vulnerable to ground troops and aircraft.
Quad Cannons: defenses armed with 4 150mm cannons that do severe damage to enemies including Battleships. In one mission the Quad Cannons must survive because without them the Solar Empire will Overwhelm the Iron Legion.
