Atari - Atari 2600 USA undumped
Confirmed to exist
Prototypes
- Aligator People/Planet of the Apes https://twitter.com/burgerbecky/status/1432228424505077762
- https://www.museumofplay.org/blog/game-saves-the-lord-of-the-rings-atari-2600/
Not confirmed to exist
Prototypes
- SwordQuest - Airworld (USA) (Proto) - only about 20% complete, no cart may have been issued
Aftermarket
- https://atarixp.com/collections/saboteur
- https://atarixp.com/collections/aquaventure
- https://atarixp.com/collections/yars-return
Unsorted
Games
- Birthday Mania
- Seal To Whales (Datatech Enterprises)
Prototypes
- AD&D - Tower of Mystery (USA) (Proto)
- AD&D - Treasure of Tarmin (USA) (Proto)
- Anteater (USA) (Proto)
- In Search of the Golden Skull (USA) (Proto)
- Mark of the Mole (USA) (Proto)
- Donald Duck's Speedboat (USA) (Proto) (1983-05-16)
- Fantastic Voyage (USA) (Proto)
- Frog Pond (USA) (Proto) - 2 versions (early and mid-level WIP)
- Gyruss (USA) (Proto) - 4 versions
- James Bond 007 (USA) (Proto) - multiple versions (supposedly there is another version with different music, too)
- Mystery Mansion (Haunted House Proto) (USA) (Proto) (1981-08-12)