Development version of the game which seems fairly complete. Only visible differences to the commercial release are main menu which is only text based without any indication of how to change game modes. Also disk includes files like "TEST.PI1" (title screen) and "CRAKOUT.PI1" (main game screen, which filename is a reference to the Gremlin Graphics 8-bit breakout game Krakout for Commodore 64, Amstrad CPC, ZX Spectrum, MSX and BBC Micro).
Many thanks to Curt Vendel for dumping this file from a former Atari developer's hard drive.