Unlock the following medals by performing the corresponding tasks:
MEDAL - HOW TO UNLOCK Gun - Get five medals for Talon Gun/Nest/Meteors destroyed. Maps Cleared - Win on 150 maps. Maps Played - Play on 150 maps. Multiplayer - Get four medals in multiplayer/Wi-Fi categories. S Rank - Earn fifty "S" ranks in Campaign mode. Tank - Produce 200 or more ground units of every type. Time - Accrue 50 hours of game play. Units Destroyed - Get 50 medals for units destroyed. Units Production - Get 50 medals for units produced.
Capture as many cites, airports, or anything that gives you money. Then, make as many rockets, artillery and anti-tank units as possible and place them in the woods, ruins, or anything else that will give you cover. When the enemy arrives, rain fire down on them.