A wonderful game for the very early Apple Macintoshes, which over a period of about a week on holiday with friends (who just sat around and smoked pot) I became very skill at. Basically, at each side of the screen is a little tower, and in between lies a landscape (like a big hill, flat land, anything really). The towers have cannons on them, and by adjusting variables like angle of fire and amount of gunpowder you take it in turns to try and destroy the other persons' tower. Of course, you have to account for wind speed first. Very simple, but paved the way for games like Tank Wars II, Scorched Earth, and even Worms.