The Atari Cosmos was a rather unique handheld/tabletop gaming system that was designed and built by Atari. It would have been released in 1981 or 1982 but Atari pulled the plug at the last minute and it was ultimate never released. Advertising was done, game packaging was produced and as many as 250 (though probably less) system units were produced as well. These are now collectors’ items.
The Atari Cosmos made use of holography to enhance the game imagery. Each game included two holographic overlays. Each one could be back-lit independently while the main game graphics were LED based like other portable games of the time period. It wasn’t really all that portable since the unit did not use batteries and an AC Adapter was required. It was advertised as being programmable and using cartridges to play different games. However, this is a bit misleading. All nine games produced were built into the system. The games themselves just came with a cartridge that did nothing more than select the game to be played and the two overlays specific to that game. Game cartridges probably would have been sold separately but at a relatively inexpensive $10-$12. It seems crazy to me that Atari would have taken this so far and then decided not to release it. It seems to me like they had already spent most of what they were going to spend in design, programming, advertising and even some production. What would there have been to lose by releasing it?
Working Cosmos units were shown at the 1981 New York Toy Fair. Critics apparently disliked it and this may be why Atari ultimately cancelled it by the end of 1981. However, Atari did receive thousands of pre-orders at that show. If you want to play one you are probably out of luck. They are difficult to find and no doubt extraordinarily expensive if you do find one. It also has not been emulated and likely won’t be any time soon, if ever. You can see some of the hologram overlays on eBay at the moment selling for $50-$60 if you go search for Atari Cosmos. If anyone has one they would like to part with, I’ll give you a few hundred Steem for it :).