You are in command of a crippled aircraft flying over an enemy city. There is nowhere to land for miles around. Luckily you have an unlimited supply of bombs. By destroying all the buildings below you as you pass over the you will make a suitable place to land. If, however, you crash in to side of a tower block you will lose one of your lives. (You start with 4 lives. 3 of them displayed as extra lives.)
You score points for every building section you destroy the number of points depending on the level and frame number. Also, you gain a life (to a max, of 5) for every 100000 points scored