Capture any cites, airports, and anything else that gives you money. Then, create as many rockets, artillery, and anti-tank units as possible. Move them into the woods, ruins, or anything else that will give you cover. When the enemy approaches, rain fire down on them.
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.