Lightly used game.  Tested on an Atari CX2600, 2600+ and 7800+. 
 
The Unknown Game
 
Completely finished but never officially released, this mysterious Datatech title was left without a name — so it became known simply as The Unknown Game.
 
Your goal is to reach the symbols at the top of the screen before your energy runs out. To get there, you must follow an invisible path across a hidden grid while avoiding UFOs and bullets dropped by birds. At the bottom of the screen, you can choose a new path before beginning your climb.
 
Each symbol changes the game in a different way. Reaching a Minus costs you 300 points, but returning to the start of your chosen path restores your energy. Reaching a Plus awards 1,000 points, and returning to the beginning of the path also gives you fresh energy. Reaching a Sword awards 500 points, makes the grid invisible, and allows every path to be walked. Return to the bottom of the screen afterward to restore your energy.
 
UFOs can be destroyed by touching them, earning 500 points, but beware: touching a non-flashing UFO will cost you one life. You will also lose a life if your energy runs out, or if the paths suddenly shift and cause you to fall. Occasionally, you may even teleport from one vertical path to another — whether this is a hidden secret or a strange glitch remains unknown.
 
The game includes a two-player mode, eight difficulty levels with increasing speed, and even features music.
 
🎮 Product Features
Collector-Quality Cartridge – Built for retro enthusiasts who value authenticity and presentation.  Correct style and brand shells.
Premium Label Finish – Sharp, vibrant artwork with durable materials (no cheap labels with inferior art and resolution)
Protective Collector’s Sleeve Included – Keeps your cartridge safe from dust, scratches, and shelf wear
Secure Boxed Shipping – Ships in a rigid box for maximum protection (not a flimsy padded mailer)
Clean, Professional Assembly – Carefully built and inspected for consistent quality
Ready to Play – Fully tested and guaranteed to work
Perfect for Display or Play – Looks great on the shelf and plays just as well
  
 Refund Policy
 
All items are guaranteed to be fully functional as described. If an item is found to be nonfunctional, a full refund will be issued upon return of the item and verification of the issue. Please note that refunds will only be granted if the item is returned in its original condition, with no components altered, removed, or replaced.
 
Shipping Policy
 
Domestic orders are shipped via USPS Ground Advantage.
In an effort to reduce waste, we may reuse and repurpose boxes and packaging materials whenever possible. All items are securely packaged and shipped in a box to ensure safe delivery.