party  games (as it was announced that Tengen would make games for the NES  behind Nintendos back) and Tetris was among the games. However,  Tengen faced a lawsuit involving distribution of its own Tetris  game. It was discovered that Tengen bought the rights from a company  called Mirrorsoft, which did not own the rights in the first place.  As a result, Tengen lost its case, the Tengen Tetris was recalled  from stores, and Nintendo released their own legitimate version for  the NES after that.