Today's RTS have NOTHING on Ground Control. Set in a distant future where corporations fight over resources, you get to command an expeditionary force that expands and get experience with every mission in the campaign. Unless they get killed, in which case they get replaced with rookies - and you will soon find out the difference between battlefield vets and cannon fodder.
Infantry is hard to hit but mostly harmless against tanks and wiped out by explosives. Tanks are vulnerable from the rear and from the air. Missile units pack a punch but die fast. Artillery is devastating, shoots in high arcs over the trees and hills, but needs scouts to spot enemies, plus you really don't want those shells landing on your own head. Avoid confusion, or half of your force gets wiped by friendly fire. Your commander is in his command vehicle on the battlefield - take care not to die. All that while the interface is unbelievably simple and all units are shockingly easy to control.
No mindless building of swarms of battleship, no spouting off tons of tanks for the final zerg. You have one to three dropships, with up to twelve units deploying - but how you configure and deploy your squads is up to you. Missions are tough, briefings entertaining, background story is fun, and the graphics are rather acceptable even today. If you like RTS, you seriously need to get this one. It remains one of the best of this genre.