A second Super Powers Play-doh set was in the works for production. Sadly, the set never saw the light of day. Based on existing pieces and information, I am able to confirm the 2nd set made it to the unpainted hardcopy stage, as this piece suggests, however it remains unclear if the set made it any further. The unpainted Parademon seen above was slated for inclusion in the unproduced Play-doh set. A second version of Superman and a Firestorm represent other characters scheduled for presence in the set. The produced 1st series Play-doh set included 6 characters, so it stands to reason that two or three additional characters would have rounded out the second set's lineup.
The photo above affords a rear view of the unpainted hardcopy. All Super Powers plastic play-doh molds featured detail located on only one side, much like the later Star Wars Play-doh sets. This explains the absence of detail on the back of the hardcopy.