Few computer games have a moral, but Moby Dick carries a message that will warm the cockles of any conservationist's heart: killing whales is wrong.
Of course, since this is a computer game killing just about everything else is fine. The idea in Moby Dick is to depth charge submarines from the destroyer you are skippering at the same time as trying to down a pink helicopter with your missiles.
Should you hit the whirlybird, the pilot will bail out: you must try to save him before he goes to a watery grave.
As you steam across the deep blue sea, it is pretty easy to get the subs with your depth charges. It's also easy to turn the great white whale, Moby Dick, into so much cat food. But while this would've pleased Captain Ahab no end, it's big trouble for you.