Ranks: ranks will come with experience again each increment of 10 will rank up your soldier and boost his skills. Soldiers gain experience by killing enemies, getting bossed around by the officer or fetching supply boxes.
(ass added in description)
i think thers a bug i have beaten about 5 levels so far and get the same card as reward every time and it gets no harder along with me not going up any ranks
 "SandStorm Racing"){kind=icon}
 "Mud and Blood 2"){kind=icon}
 "The Necronomicon"){kind=icon}
 "Red"){kind=icon}
 "Parachute Retrospect"){kind=icon}
 "Epic war"){kind=icon}
 "Brute Wars"){kind=icon}
 "Runescape"){kind=icon}
 "The Newgrounds Card Game"){kind=icon}
 "Bubble Tanks 2"){kind=icon}
 "Nano War"){kind=icon}
 "Mr. Bounce"){kind=icon}
 "Protector"){kind=icon}
 "Open Doors"){kind=icon}
 "Typing Ninja Hunter"){kind=icon}
 "Music Catch"){kind=icon}
 "Dino Run"){kind=icon}