In this game your mission is to guide your submarine and pick up frogmen as they come into view on the screen. Meanwhile enemy aircraft fly overhead dropping depth charges. The sea is populated by submarine-eating fish which you must avoid or torpedo.
When you have rescued several frogmen you go up a level and the game becomes more difficult. At the top of the screen are your score, highest score and the number of remaining lives. You have three lives.
After a while I found I could frequently get up to the next level with all my lives intact. However, the game didn't change. I would have preferred a different sea monster, giant squids or crabs, for instance.
I found the game rather tame after the initial interest had worn off. The screen graphics are not outstanding and the game is short on instructions. The inlay card gives no instructions at all. Only when you load the program do you get two screens of instructions. The inlay card should at least say whether joysticks can be used. All in all I was not terribly impressed by this offering.