The six games for the Atari 2600 VCS are: 3D Ghost Attack!, 3D Genesis, 3D Havoc, Atom Smasher, Depth Charge, and S.A.C. Alert. The 3D games are the first and only 3D games for the platform (they come with paper glasses), Depth Charge was originally designed to be the first head-to-head game where each player has their own console and TV, and S.A.C. Alert was meant to be used with the Amiga Joyboard, the horrible joystick platform you stood on and whose only game actually released was the skiing game, Mogul Maniac. Keep in mind that these six games from the early 1980s are all in various states of completion and Video Soft is rather vague about how playable each one is. Prices range from $30 to $50 plus shipping and handling (if you buy the full $230 set, shipping is free), and each of the six games is limited to a production run of 100 copies, which includes a cartridge, manual and box. Apparently after a particular game sells out, the ROM will be made available to everyone. I'll leave it to this snippet from the Video Soft Website to provide a bit more detail:
"Lord of the Dungeon" was released in limited quantities as a homebrew back in 2000 from the 1984 unreleased original prototype for the ColecoVision from Probe 2000, which would have been the first ever battery backed cartridge. These are rare, rare images since so few people have it and it's unsupported by any emulator. You can see it would have been a phenomenal Wizardry-like RPG for a console well before anything like it on the NES!
AtariAge, the premiere home of all things Atari consoles, has several new homebrew cartridges available for the Atari 2600 VCS, as well as a special edition of Atari 7800 Beef Drop, complete with enhanced graphics and POKEY chip sound!
Also, be sure to check here and here for information of a very impressive looking 1989 unreleased 85% complete prototype of Missing in Action (based on the "classic" Chuck Norris film) for the Atari 7800, also available for purchase or free ROM download for use with a Cuttle Cart 2 or emulator. (Keep in mind that emulation does not yet display the game properly, so the screenshot to the left and any that you see right now not taken directly off of a TV screen do not show off the game to its fullest)
The full release with all the details: