For The US market this is the game of choice as fare as rarities are concerned, for the starter collector you should hunt the Brazilian version of the game serpent do poder, which also was considered rare, until they started to appear on eBay on a weekly basis under the title "Power lords", so although also uncommon, you shouldn't be paying anywhere near the price of power lords for serpent by possibly 10/1 what makes it all the more unusual, is there was no European release of this game and although it was voice enhanced it would have easily ported across to the European market as the voice is not necessary to play the game. Probe 2000 were the developers of this cart, who I believe was a subdivision of Magnavox with the intention of licensing games for other system than the Magnavox systems such as the colecovision where they released the game "war room", which is rumoured for the odyssey2/videopac, but it seems unlikely this ever got anywhere, to the point where even diehard hopefuls no longer have this on their lists of prototypes. The game was a franchise based on a popular cartoon toy collection of the time.

The point of the game was to guide Ned over the stones which each had numbers, there's multiple subgames included such as Name the Shape, Multiplication runtrhorugh and Function Machine.