Why is Color A Dinosaur considered rare?

[Gameguy]

They couldn't have sold well. I also think that since they're unlicensed games they prolly had low production runs, as well.

They were sold mostly to rental stores, it wouldn't surprise me if some stores bought multiple copies before they knew how terrible it was. It was $200 originally but it was discounted later in it's life, I think it was dropped to $50 at one point. It sold well enough to have several label and circuit board variants. Again, there are plenty of rental exclusive games that aren't as valuable as this game.

Just something of interest, the Genesis version of Action 52 was developed by the same people who made Color a Dinosaur. And they're still making games today.
http://en.wikipedia.org/wiki/FarSight_Studios


EDIT: I found an ad which lists the price of Action 52 at $79.99. It shows that the price was dropped several times while still being produced.
http://i60.tinypic.com/i513kz.jpg