Why were only only 300,000 copies of Uniracers were produced?

It didn't sell well due to poor review scores
There was a disagreement between DMA Designs and Nintendo
DMA Designs was sued by Pixar, preventing more copies from being produced
No public information is available

Explanation

Only 300,000 copies of Uniracers were produced because DMA Designs, the developer of the game, was sued by Pixar. The lawsuit alleged that the game's unicycles resembled the stars of Pixar's then-upcoming movie, Toy Story. As a result, DMA Designs had to stop production of the game, limiting the number of copies that were available in the market.

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