Cannonball Blitz is a game by Olaf Lubeck and released in the early 1980s by Sierra On-Line (then known as "On-Line Systems") for Apple II, VIC-20, and TI-99/4A computers. The game is a Donkey Kong clone, although cannonballs and cannons replace barrels and a soldier replaces the large ape. On the first level, the player character catches a flag instead of rescuing a girl. There were three different levels, the third of which is particularly challenging. After completing the third level, the player views a small celebration scene and then restarts at the first level. Repeated levels only differ from those of the first round in the harsher timing patterns of the game. Source: Wikipedia, "Cannonball Blitz", available under the CC-BY-SA License.