atari2600land has possibly created the first ever 1k sized bBasic game in history.

Catch bananas with Mr. Zyx’s mouth. Get 10 points for every banana (read: yellow line) you catch (read: eat.) If you miss a line, no more bananas will fall from the screen so you would have to reset the game.

http://www.atariage.com/forums/topic/188785-the-first-1k-bb-game/