It is 2056 A.D. A plague has swept the world, killing or mutating everything in it's wake. The infected become unimaginable horrors that rend the flesh from human bones. These nightmarish creatures have almost completely wiped out the human race. Your small army is stationed at Fort Apocalypse. Defend it at all costs and eradicate the infected in the area or the human race will perish.
Marines: Basic infantry.
Jaguar Light Vehicle: Extremely fast raider, useful for luring and hit and run attacks.
Incinerator Squad: Extremely powerful but short ranged and slow
MTB-09 Tank: Slow, heavily armored and powerful.
Minigun Installation: extremely powerful and long ranged MG. Has only 1 speed though, so use for defense only.
Infected: Extremely fast and powerful melee warrior.
Infected: Same as the above only with a VERY short ranged gun.
Tip: Use Jaguars to lure infected to Fort Apocalypse. It's heavy defenses will make short work of them.
EDIT: Added Observation Chopper and new unit for the survivors, added mountains, added script (It's my first script, so go easy on me).