I’m a bit late to the trough on this one, but it’s worth calling back to the Video Game History Foundation’s recent release of over 100 ROMs and other data from the Sega Channel, that short-lived service that allowed subscribers with a model peripheral to play downloaded games over a cable TV line. It was kind of like a terrestrial version of Nintendo’s Satellaview service, but also one that wasn’t locked to Japan.
Some of these games were never released outside of the Sega Channel, and the VGHF also has unreleased prototypes for public perusal through their own archived collection and an association with Gaming Alexandria. Two particular finds are a hitherto undiscovered variant of a Garfield game and a Genesis Flintstones game that, at a glance, seems to be based off of the John Goodman movie. An abandoned project also in the collection is a Sega Genesis web browser, which would have been quite a thing to see back then. Notably, Gaming Alexandria’s torrent of the complete data is only 147 megabytes, which isn’t such a large download all told.

The VGCF prepared a 58-minute promo video for their project here, with commercials and other content that are, ah, very nineties in style.
As an aside, I was shocked to see the company General Instrument come up early in this video. Weren’t those the people who made chips for pre-VCS dedicated game consoles back in the 70s? As it turns out, yes they were (PDF link)!