There are six medals that can be earned. They are shown just below the red trident arrows pointing out the storyline missions. They do not seem to be based on actual US Navy medals.
The medals do not represent specific accomplishments, but instead build up as you accomplish certain things. The medals start accumulating with the second one. Then the third will light up, and the fourth, and so on. On Gameprom's high scores site, nobody has won more than four medals. Once you win a medal, it will stay lit until the end of the game.
The first medal can be won by completing all the missions. The last medal can be won once the game has been completed and you complete all the missions again.
Here are ways to win medals:
- Get all three Navy Bonus multipliers. Doing this with different lives allows you to get additional medals.
- Complete the first storyline mission and kick the ball into the helicopter after the back door lights up.
- Complete the second storyline mission and kick the ball into the submarine after its door lights up.