Order this product between now and 12/31/2012 and receive a $5 promotional credit good towards any of the "Editor's Choice" game downloads in the month of January 2013. You will receive an email with your promotional code and redemption instructions. Qualifying credits for this promotion may only be used one at a time. Here's how (restrictions apply)
Games do not appear to be able to be downloaded on Steam.
List of Games below and on following comment.
List of Games
Sega Genesis Classic Pack 1:
Ecco the Dolphin
Shinobi III: Return of the Ninja Master
Space Harrier II, Vectorman
Sega Genesis Classic Pack 2:
Alex Kidd in the Enchanted Castle
Galaxy Force II
Super Thunder Blade