Unlock Boss Cards
During with foght with a boss, you have to take him out quickly to get its card. Grenades, the Metal Slug and special weapons are good for this. A message will appear on screen letting you know that you have the card.
Unlock Dungeon Mission
During Mission 5 the dungeon card. Once you complete mission 5, go to the mission select screen and to the top left there should be an extra mission called dungeon.
