Nintendo's Tetris is one of the best-known computer games in the world, but the original version - released by Russian developer Tengen - is incredibly rare.
Just three copies are known to exist of the original "Soviet mind game", one of which could see huge bids by the time an online auction closes on January 20.
After the game was developed by a Soviet Academy of Sciences researcher in 1988, Nintendo argued that it had the distribution rights to Tetris on its NES console, resulting in a long series of law suits between the two companies.
In 1989 an injuction was issued that barred Tengen from distributing the game, and ordered all existing copies to be destroyed. Though 268,000 were recalled, approximately 100,000 copies had already been sold in shops and have since become a highly valued collector's item.
Adding to the game's appeal for collectors, the Tengen version is reportedly much more enjoyable, with better gameplay and a two-player co-operative mode.
The example at auction, a prototype copy, was first seen on eBay according to news.com.au, where it appeared with a $40,000 reserve. However, the present auction house's Mike Kennedy told the website that it now has a "much more reasonable and reachable reserve price".
Iconic computer technology is fast emerging as a new area of collecting, with an ultra-rare copy of Final Fantasy II for the SNES appearing on eBay with a $50,000 reserve in August 2012.
Apple-1 computers - the first made by Steve Jobs' leading brand - are possibly the most valuable computing collectible, after one sold for $518,529 in November 2012, raising the world record by 38% in just five months.
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