This is a very early WIP version of Pengo. While an actual prototype for this version has not yet been found (if it was ever burned onto EPROMs), it was featured in the Atari In-House Promo 2nd Quarter 1983 video which was made to show other Atari employees what everyone was working out at the time. This version has many differences from the final.
The first and most interesting difference are in the
status bars at the top and bottom of the screen. The WIP
version has light gray status bars instead of black and P E N G
O written on the top. Underneath the game name appear to
be three sets of game variables written in hex (most likely
coordinates) and then a rom of flag icons (although flipped from
the final version of the game) used as a border. The
bottom status bar has a row of flags then the number of players
and the game level listed. The lives, eggs, and level
counters are all missing as is the score.
Pengo himself looks a little different but is fairly
close to his final form and appears to be missing the whites
around his eyes. The ice blocks have dark highlights
instead of white (although this could be due to the poor quality
of the video), and it appears that the diamond blocks haven't
been implemented yet. The Snobees and their eggs are also
absent. Pengo appears to just be able to move around and
push ice blocks in this version.