This prototype was found at a flea market in Kenosha, WI, in a lab loaner cartridge case.
The gameplay consists of one screen in which Charlie Brown must fly his kite while avoiding birds, balloons, rockets, and other obstacles. There is a wind gauge at the bottom of the screen that indicates wind speed and direction. A timer counts up, but doesn't seem to affect gameplay. Pushing up and down on the joystick will let the string in and out, and moving left and right affect the direction of the kite flying. There is no sound in the game, and it seems very incomplete at this stage. Screenshot used with permission from Atari 2600 Connection.