The Sega Channel was way ahead of its time. The service allowed Genesis / Mega Drive owners to download games to their consoles using a cable connection and was a forerunner to the digital distribution systems we all take for granted today.
Two unreleased Sega Channel titles have just been discovered and preserved, thanks to the efforts of Sonic Retro Forums member ndiddy. Taking an image file uploaded by another community member, RisingFromRuins, ndiddy has been able to extract Klondike Solitare and The Chessmaster.
"I was able to reverse engineer the tool that encodes the image file (NSF.EXE) and wrote my own that reverses this process," explains ndiddy. "There's a couple unreleased games in there (Chessmaster and Klondike) and a few "test drives". The .bin files are decompressed, while the .sa files are compressed (same as the compressed .sa files from the Sega Channel dev disk). Files 0 and 1 are Sega Channel menu/help files that won't load in an emulator."
The game files can be found here.
Billy Time Games has also uploaded some gameplay footage for both titles: