What the heck do I have?! Is this a prototype??

[Satoshi_Matrix]

Sorry for the wait. Here's some photos of the entire lot.

All 14 games


H.E.R.O proto(?) compared to Kaboom for the 2600, also by Activision


Comparison of the edge connectors. H.E.R.O on top.


The back of the H.E.R.O proto. Pitfall II also looks exactly like this.


Here's Pitfall II. It lacks the extra info H.E.R.O has, but considering it's age, the top sticker could well have simply fell off and I didn't notice it.

H.E.R.O and Pitfall II carts


The tops of both H.E.R.O and Pitfall II completely lack end labels. Most of the others say <- Left Cartridge. Not these.


So this presents the question: Do I have two prototypes here? They look so very different from the others.