Achieve the S rank
Free Penguin Village
Collect 38 placards in a playthrough
Drive an enemy tank
Reach the final base without driving
Reach the final base by a rental tank
Complete the game without merchant weapons
Achieve the A rank
Achieve the B rank
Shut down the first enemy base
Shut down the second enemy base
Shut down the third enemy base
Shut down the fourth enemy base
Shut down the underground enemy base
Shut down the twin enemy base
