To unlock Medal Ranks, you complete the following tasks:
Green Status: you get in the beginning
Veteran Status: get 4 medals in the category
Elite Status: 32 medals in the category
Legendary Status: 64 medals in the category
To get Ranks and Commanding AI Units, do the following:
Private: lead One Man, 0 Medals (you get it at the start)
Sergeant: lead Two Men, 20 Medals total
Captain: lead Three Men, 100 Medals total
General: lead Four Men, 300 Medals total
To unlock powerful weapons, cpmplete the following tasks, get a particular weapon and put it instead of the previous one:
Elite Assault Rifle: get Legendary Status in Frenzy
Flechette Shotgun: get Legendary Status in Regulator
Guidable Rockets: get Legendary Status in Demolition
Particle Beam Rifle: get Legendary Status in Marksman
Precision Blaster: get Legendary Status in Gunslinger
Vehicle Regen: get Legendary Status in Technician
To unlock medals, read the following and do the indicated task:
Demolition: deal 4 critical hits on vehicles with Rocket Launcher (3 in Elite)
Endurance: get 12 points (9 in Elite)
Frenzy: get 12 kills with a Blaster Rifle (9 in Elite)
Guardian: get 24 points (18 in Elite)
Gunslinger: get 6 kills with a Pistol (4 in Elite)
Marksman: get 6 headshots with a Sniper Rifle (4 in Elite)
Regulator: get 8 kills with Shotgun (6 in Elite)
Technician: get into 1 vehicle (without change for Elite)
War Hero: get 36 points (27 in Elite)